Botanical Bits--monthly columns written by Nebraska Statewide Arboretum staff and distributed by University of Nebraska Institute of Agriculture and Natural Resources
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October 2008
Plains-Hardy Shrubs for Fall Color
Jim Locklear, Nebraska Statewide Arboretum
Autumn is a wonderful season in Nebraska , when our prairies take on their subtle end-of-the-summer glow. But, truth be told, most of us still desire the bold show of color that other parts of the country enjoy in the fall, and our thoughts naturally turn to trees like maples and gingko and sweet gum.
Shrubs are sometimes overlooked as a source of fall color, but they have a lot to offer, particularly here in Nebraska where our cold, heat, dryness and wind may limit the palette of trees we can use. Here is a sampling of plains-hardy shrubs with great fall color.
Black chokeberry ( Aronia melanocarpa ) is a medium-sized shrub (height 4-6 ft.; spread 3-5 ft.) with multiple seasons of interest. Starting with showy clusters of white flowers in early summer, followed by dark purple fruits greatly appreciated by robins, this adaptable shrub closes the growing season with beautiful wine red fall foliage. Black chokeberry is adaptable but prefers moist, well-drained sites in full sun to part shade and is most effective when massed in the landscape and allowed to follow its natural tendency to spread by suckering. It was selected as the shrub of the year by the Nebraska Nursery & Landscape Association in 1998.
As a relative of the immensely popular burning bush ( Euonymous alatus ), it should come as no surprise that eastern wahoo ( E . atropurpureus ) has great fall color. This North American native grows as a small tree in the southern part of its range, and as a large shrub (height 6-15 ft.; spread 4-12 ft.) here on the Plains. The bright red of its fall foliage is amplified and extended by abundant clusters of pendent, scarlet fruits that persist after the leaves have fallen, providing color even into mid-winter. Eastern wahoo is effective as an accent plant or massed wherever a bold, surprising splash of color is desired. It prefers deep fertile soils in full sun to part shade.
The American Southwest has a wealth of shrubby oaks, but Gambel oak ( Quercus gambelii ) is one of the few tough enough to make it on the Upper Plains. Forming thickets in its natural habitat on the foothills and lower slopes of Rocky Mountains, Gambel oak makes an attractive, large shrub (height 8-15 ft.; spread 10-15 ft.) in the landscape, with dark green foliage that reminds you of miniature bur oak ( Q . macrocarpa ) leaves. Like most oaks, its fall color is often subtle and varies from individual to individual, but nice burgundies and orangish-reds can be seen in wild populations. Its small acorns are a favorite of blue jays. Gambel oak is drought tolerant and grows best in full sun to part shade.
While America 's native viburnums occur most commonly in the eastern United States , rusty blackhaw viburnum ( Viburnum rufidulum ) flirts with the edge of Plains. One of the most drought tolerant species in the genus, rusty blackhaw viburnum (height 9-15 ft; spread 15 ft.) has neither the showiest floral display nor heaviest fruit production. Still, noted horticulturist Michael Dirr ranks it as one of his favorites. The glossy dark green, leathery foliage is reason enough to grow it; the rich burgundy tones of its fall foliage is icing on the cake. It grows best in full sun to part shade.
September 2008
Selecting Plants for a kid's yard
Christina Hoyt, Nebraska Statewide Arboretum
Kids used to be told “Go outside and don't come home till sunset.” With that prompt, all the nearby creeks, fields, forests, parks and gardens were transformed into special and wondrous places where a child's imagination could be acted out.
But with television, computers, video games, organized activities and continuous fears of “stranger danger,” kids find themselves spending most of their time indoors. Recent studies have linked an increase in childhood obesity, ADD symptoms and childhood depression to this phenomenon and shown that time in nature can actually relieve some of these symptoms. One step of re-connecting kids with nature is creating and preserving meaningful nature experiences for them close to home.
Our yards have become increasingly manicured; with tidy lawns, carefully pruned shrubs and limbed-up trees all designed for adult aesthetics. By looking through a child's eye, and make a few inviting changes, yards that were once “off limits” can become an inviting place for children to explore nature—and it doesn't have to be difficult. Instead of buying that box-store swing set that a child quickly outgrows, use these guidelines to create a more lasting play environment.
While your kids are young, give up your notion of a perfectly tidy landscape—especially a highly manicured lawn and the chemicals it takes to make it look that way.
Plant a diversity of shrubs, perennials and trees that will encourage wildlife, including pollinators such as birds, butterflies and insects.
Stay away from poisonous plants when you have young children, like yew and monkshood.
Allow “rough-edges” that aren't manicured. Areas planted as a mini-prairie, wildflower gardens or un-mowed areas of lawn work well for play and imagination.
Give children spots of their own to dig, plant, build and play.
Instead of pre-built play houses or swing sets, give children materials to build their own. For young children, create the structure's outline and let them create their own walls out of blankets or sticks. Let older children build the whole thing. Forts don't have to be built in trees to be magical places.
Learn to garden together. Gardening can teach skills like patience and stewardship, and they build self esteem.
A garden doesn't have to be big to be effective. If your neighbor has children, perhaps share a plot of ground together to encourage teamwork and sharing.
Most kids can identify exotic plants such as a giant sequoia or palm tree, but not the plants found in their own state, like little bluestem or oak trees. Use native plants wherever possible. These plants make better habitat for wildlife and require little maintenance. (A recent study found that most children could identify 100 corporate logos but less than 10 plants native to where they live.)
Add loose parts—sticks, branches, seeds, rocks and other objects that are movable and can be used in imaginative play.
Use sensory plants in your yard. Children love plants that have interesting scents, textures, colors and smells
August 2008
Prairie Dropseed, an Elegant Prairie Grass
Bob Henrickson, Nebraska Statewide Arboretum
Prairie dropseed, Sporobolus heterolepis, is one of the most elegant prairie grasses for the landscape, and also one of the most dependable. It has a graceful, weeping habit and shiny, ribbon-like leaves. The common name refers to the teardrop shape of the seed. The genus Sporobolus combines the greek “ sporos ” meaning seed with “ bolos ” for throwing, referring to the ease with which ripe seed are pushed from the base of the grass spikelet. The seeds are very nutritious and a favorite of some birds. There are nine species of dropseed native to Nebraska , two annuals and seven perennials. All are useful in restoration plantings but prairie dropseed, Sporobolus heterolepis , is the one that deserves a space in any modern landscape.
By mid-spring, several weeks earlier than other warm season prairie grasses, it forms a dense tuft of bright green foliage with a very soft appearance. The fresh new growth combines well with spring-flowering plants like dwarf iris and pasque flower. Though it takes several years to grow into a mature plant, it doesn't need dividing and doesn't die-back from the center. By mid-summer it forms an attractive, fountain-like mound of foliage up to 2' high and wide. It is attractive enough for a formal garden or can be planted in large groupings for a prairie-style lawn or meadow garden. In late summer into fall, the foliage can turn orange to copper. Airy, open flower panicles high above the foliage emit a pungent fragrance when bruised, often described as a combination of cilantro and fresh popcorn. The scent is faint, but noticeable even when passing by a mass of seedheads on a cool, dewy morning.
This grass will reward you with a veil of abundant seedheads when planted in full sun and improved soils. It will grow well in part-shade and clay or sand, but flowering and fall color may be reduced. For plants growing in harsh, dry areas or during extreme droughts, provide extra water during the summer months to improve flowering. It makes an outstanding border plant and a complement to perennials with strong upright growth or those with broad foliage. I like to combine it with vertical plants such as shell-leaf penstemon or gayfeathers, or as a border plant to hide the bare legs of leadplant or prairie asters. The veil of mist-like flowers combines well with other mid to late summer bloomers like nodding pink onion and stiff goldenrod.
JULY 2008
Getting Buggy about Summer
Justin Evertson, Nebraska Statewide Arboretum
When it comes to insects and spiders (arthropods) in the landscape, many people tend to think of little critters that cause problems and that we wish would go away. We think of stings, itchy bites, damage to plants/vegetables and the sheer creepiness of so many species. That's too bad, because the vast majority of arthropods are either benign or are actually very beneficial to the world around us. It's easy to enjoy butterflies, with their colorful wings and fluttering movements. We should also learn to enjoy many of the other arthropods in the garden. A few that are worth a closer look include:
Goldenrod Spider. The goldenrod spider ( Misumena vatia ) is a type of crab spider that exists throughout North America where it's typically found waiting for prey on either white or yellow flowers. What is most fascinating about this spider is the ability of the female to change color from yellow to white, depending on the type of flower it inhabits. This camoflauge can make the spider nearly invisible. A goldenrod spider can grow to about the size of a dime and is often found on daisies and goldenrod flowers, thus its common name.
Soldier Beetle. The soldier beetle ( Chauliognathus pennsylvanicus ) gets its common name from a bright red species in England that reminds people of a soldier's coat. In Nebraska , the beetle looks quite similar to a lightning bug (and is related to it, but doesn't “light up”). Soldier beetles are beneficial in two ways: they are predacious and eat many problematic insects including aphids, and they help pollinate flowers when feeding on nectar. Soldier beetles are found most often on yellow-flowering plants such as false sunflower, goldenrod and helenium. They are also quite common on milkweeds.
Red Milkweed Beetle. Just as its name implies, the red milkweed beetle ( Tetraopes tetrophthalmus ) is found on milkweed plants, typically the common milkweed ( Asclepias syriaca ). It is thought that the beetle, much like the monarch butterfly, gets a measure of protection from predators by feeding on the milkweed plant and thus becoming very distasteful. The beetle grows to about 1/2” long, possesses distinctive annulate (segmented) antennae and is often found in great congregations on host plants. Although its bright red and black-dotted markings give it an intimidating appearance, this beautiful insect is completely harmless.
Insects and spiders should not be thought of primarily as things to kill or avoid, but rather should be enjoyed and celebrated. As summer heats up, take time to explore the fascinating world of the insects around us. Check out the myriad forms colors, shapes and sizes. It's truly an amazing world, and one which none of us can do without.
Coffeetree - Winter Revelations, Justin Evertson
Winter - cold and gray and often foreboding. But also a good time to bundle up and get close to trees. For it is not until after the autumn drop of leaves, that the attractive bark and structural form of many trees are better revealed. One of the best trees for winter revelation is the Kentucky coffeetree ( Gymnocladus dioicus ). Native to the eastern third of Nebraska , coffeetree tells a winter story unlike any other tree.
Coffeetree has the largest leaves of any deciduous tree that grows in North America . The compound leaves, containing numerous small leaflets, can actually grow to two feet long and 18” wide. When these leaves fall, a tree of coarse texture is revealed. When young, the tree looks quite awkward and naked. In fact the scientific name Gymnocladus , means “naked branch”. But just like the ugly duckling that grew into the beautiful swan, so too does the coffeetree. Its mature winter outline is nothing short of magnificent. The plate-like bark of coffeetree is also quite attractive. In fact the low winter sun angle greatly accentuates its finer textures so that it appears almost like stucco applied to the tree.
Coffeetree is named for its hard seeds (the size and color of Milk Duds) that were roasted and ground by early settlers to create a coffee-like drink. The tree has both a male and female form and it is only on the female tree that its large but attractive seed pods are produced. The brown pods (5-7” long) typically hang on the tree through much of the winter, providing another identifying characteristic for the tree. The pods tell a fascinating story of evolution and survival. Over hundreds of thousands of years, the tree evolved with large herbivores such as rhinos, mammoths, horses and camels that long ago disappeared from the North American plain. Many of these “mega fauna” would have fed on the energy-rich seed pods in late winter and early spring. As such, the seeds had to be very hard to survive chewing and digestion so that they could sprout later in the fertile pile of the animal's dung. Although the animals long ago disappeared, the tree managed to survive to help tell us the story of a forgotten time.
Coffeetree is one of the best trees for planting in Nebraska . It is long lived, it tolerates the worst of Nebraska 's weather extremes and it will grow in a wide variety of soils. The tree also develops a nice golden-yellow early fall color. The coffeetree is one of the last trees to leaf out in the spring and one of the first to drop leaves in the fall. This evolutionary adaptation helps it avoid late-spring and early-fall freezes and also makes it very resistant to ice-storm damage. Be patient in the spring, however. Many a coffeetree has been cut down by people assuming the slumbering tree was dead.
EarthKind TM Roses
By Kathleen Cue, UNL Extension, Douglas/Sarpy County
The rose is America 's most beloved flower. It also has the reputation for being persnickety, fussy, and downright difficult to grow. Disenchanted gardeners can now consider growing EarthKind TM Roses. Texas A & M University started the EarthKind TM Environmental Stewardship Program to promote landscape sustainability, utilizing tough rose varieties to launch the program. Roses deemed EarthKind TM are noted for their winter hardiness, disease resistance, drought tolerance and reliable flowering.
The most extensive testing of EarthKind TM Roses outside of Texas is at Haworth Park in Bellevue , NE. This joint venture between the Omaha Rose Society and UNL Master Gardeners of Douglas/Sarpy County began in the spring of 2007. Thirty rose varieties were planted and evaluations will take place over the next two years. Plans are underway to add 20 more varieties from the Northern EarthKind TM Research Program from the University of Minnesota .
Utilizing the EarthKindTM technique, 3 inches of compost is first worked into the soil. Roses are mulched with 3 inches of an organic mulch and given 1 inch of water per week for the first growing season. After that, the roses are on their own--no watering, no spraying and no fertilizing. This isn't to say these roses will never get black spot or aphids, but by giving special thought to the growing environment, the roses rebound quickly from pest problems. Thus far, some of the rose varieties that are performing beautifully include 'Barn Dancer', 'Belinda's Dream', 'Knockout', 'The Fairy', and 'Princess Verona'.
Haworth Park is located next to the Missouri River, just off Highway 370 in Bellevue . The EarthKind TM Roses test site is open to the public during normal park hours. An open house is planned for Friday, September 19, from noon to 5:00 pm.
Botanical Bits on PERENNIALS/GRASSES/VINES
Bush Type Clematis: A Garden Treasure
Bob Henrickson , Nebraska Statewide Arboretum
Clematis is often called “queen of the vines,” and for good reason. I can't think of another perennial vine that offers as much versatility in both form and color.
Clematis (KLEM-a-tis) is a member of the ranunculaceae (buttercup) family. One recent classification recognized 297 species of clematis, not to mention the numerous garden hybrids. Many gardeners think of clematis as vines that twine around a mailbox, trellis or arbor, producing masses of large, open-faced flowers. It's true that most clematis are woody deciduous climbing plants, however a few are herbaceous, dying back to the ground in winter and emerging from the base in spring.
The clematis plants I'm going to describe are the shrub or upright clematis that are great for individual specimens or allowed to weave as a groundcover through a shrub or perennial border. These shrubby plants have handsome, compound leaves and showy bell or urn-shaped flowers, followed by silky seed heads. I have found these bush clematis to be hardy, very easy to grow and long lived in the garden when provided full sun to part shade and rich, well-drained soil. The shrub clematis selections have become easier to find in the garden center and recent breakthroughs in breeding have greatly expanded the selection of these valuable yet overlooked garden plants. I will focus on varieties that are both available and suitable for the Great Plains garden.
Fremont's Clematis , Clematis fremontii
A Plains native, this clematis grows like a herbaceous perennial, up to 20” high. Its thick, leathery leaves emerge in early spring, followed by attractive 1” urn-shaped flowers with thick blue to purple petals, blooming in May. Like most clematis species, it can take several years to grow into maturity. This long-lived gem is one of my favorite garden plants and combines well with other spring bloomers, such as pasque flower or prairie smoke. It was named in honor of John C. Fremont, the famous explorer of the American West and the first to catalog this plant in the 1840s.
Ground Clematis, Clematis recta ‘Purpurea'
Ground clematis can be trained to climb, but is usually left alone to crawl along the ground or tumble down a bank or low wall. It has attractive rosy-purple new leaves in spring that turn green as the season progresses. In late spring and early summer it produces masses of small, white, star-like flowers. The vanilla-scented flowers are followed by silvery seedheads.
‘Mongolian Snowflakes' Clematis, Clematis hexapetala ‘Mongolian Snowflakes'
This shrubby clematis grows into a sprawling 3' high mound of rich, dark green linear leaves with parallel veins. In late spring, it is topped with clusters of 1” white, fragrant flowers, soon followed by feathery, bright silver seed heads. Both the flowering stems and the seed heads are excellent as cut flowers, each with a long vase life. This drought tolerant clematis is easy to grow in any sunny, well-drained site. ‘Mongolian Snowflakes' was selected for its copious clusters of larger 1 1/2” flowers.
‘Mongolian Gold' Clematis, Clematis fruticosa ‘Mongolian Gold'
This is a dwarf shrub with woody stems up to 3' high and dark green foliage. In late summer, the clumps are topped with 1” yellow, intensely fragrant, bell-shaped flowers. Its non-clinging stems can lean against a support or allowed to tumble over a low wall. It is very drought tolerant and cold hardy and grows best in full sun and well-drained soil.
Rock clematis , Clematis columbiana var . tenuiloba
This prized rock garden clematis has ascending or erect 6” non-vining stems with longer stems trailing or leaning on neighboring vegetation or rocks. The slender, light blue flowers are held above the foliage in a nodding fashion. Prefers part shade and thrives in clay, limestone rubble or garden loam. When well-established this clematis is very long-lived. This lovely Black Hills native is hard to find, but worth looking for. Sugarbowl Clematis , Clematis scottii
This beautiful rock garden clematis is from the southern foothills of Colorado 's Front Range , yet its winter hardy to 30 below. This non-vining clematis is slow to get going, but is a long-lived perennial when grown in rich, well-drained soils and full sun to part shade. It has showy 1” deep blue, bell-shaped flowers followed by fuzzy seedheads. Tube Clematis , Clematis heracleifolia var. davidiana
This China native is a tough clematis, with handsome, dark green leaves forming a 4'high perennial shrub. In late summer it is topped with lightly scented clusters of small, pale blue flowers that open with recurved petals. This easy-to-grow clematis needs full sun or the blooms will be sparse and the plant will be floppy. The seedheads are also very attractive. The cultivar ‘China Purple' has deep purple-blue flowers.
Bush Clematis , Clematis integrifolia
This is the most common herbaceous clematis, growing up to 2' tall with nodding steel blue flowers over upright clumps with many stems. This summer bloomer needs full sun or the plant will be floppy. If you prune the plant back after flowering, it will bloom again in late summer or early fall. Look for splendid new cultivars of bush clematis hybrids, such as ‘Olgae' with large blue, bell-like flowers; ‘Rosea' with clear sugar pink bells; ‘Arabelle' with deep blue-mauve 3” flowers; and ‘Hanajina' with purple-pink bells.
Mrs. Robert Brydon Clematis, Clematis x jouiniana
I grow this hardy, easy-to grow clematis as a groundcover between large shrubs. It's a vigorous, non-clinging vine with many small bluish-white flowers in late summer to fall. In cold climates it dies back to the ground in winter and you'll have to cut the stems back in early spring. Growing to 10' it can be tied, allowed to cascade over a wall or used as a groundcover over an old tree stump.
Botanical Bits on SEASONAL topics
Botanical Bits on MISCELLANEOUS topics
Bees: A Buzzing Garden is a Happy Garden
Kristina Jensen, Nebraska Statewide Garden
As Nebraskans gear up to celebrate Wildflower Week (May 31-June 8) a key ally should also be considered for praise—the bee.
Bee pollination accounts for $15 billion in added crop value in the U.S. In more realistic terms, about 1 in 3 bites of food is in some way affected by honey bee pollination. And at a time when Colony Collapse Disorder and other stressors such as pathogens, parasites and the environment are plaguing pollination, bees need all the help they can get.
So what can the average person do? First, be conscientious of pesticide application. Only do so when necessary and try to avoid mid-day when bees are out foraging for nectar. Another thing is to plant good nectar sources. Here's where the wildflowers come into play. Native plants have more nutritious pollen and nectar because they've been unaltered by breeders. And since they're adapted to growing in a certain area, they require less fertilizer and pesticides. Need some ideas? Try the following sure-fire bee-attractors:
Butterfly milkweed— Asclepias tuberosa . Clusters of bright orange flowers in mid-summer. 1' h, 1' w. Perennial.
Plains coreopsis— Coreopsis tinctoria . Daisy-like flowers with yellow petals around dark red centers in summer. 2' h, 1' w. Re-seeding annual.
Rocky Mountain bee plant— Cleome serrulata . Pink to lavender spidery flowers in mid-summer. 2' h, 2' w. Re-seeding annual.
Purple prairie clover— Dalea purpurea . Tiny, bright purple flowers on dense, cone-like heads in mid-summer. 1' h, 1' w. Perennial.
Purple coneflower— Echinacea angustifolia . Pink to lavender petals around an orange-brown cone in early summer. 1' h, 1' w. Perennial.
Sunflower— Helianthus annuus . Golden petals around a brown-purple disk in late summer. 10' h, 3' w. Annual.
Beebalm— Monarda fistulosa . Fragrant, spidery, lavender flowers in late summer. 2' h, 2' w. Perennial.
Beardtongue— Penstemon grandiflorus . Lavender, snapdragon-like flowers in late spring. 2' h, 1' w. Perennial.
Black-eyed susan— Rudbeckia hirta . Yellow petals around a chocolate center in summer. 2' h, 1' w. Short-lived, re-seeding perennial.
Goldenrod— Solidago sp. Bright yellow plumes in late summer. 2' h, 2' w. Perennial.
As bees busily buzz around these plants, keep in mind that almost every species is gentle and will not sting. Their main goal in life is to collect nectar and pollen for them and their young—with by-products for people to enjoy!
It's a kid's yard, Christina Hoyt
It used to be that kids were told “Go outside and don't come home till sunset”. With that nearby creeks, fields, forests, parks or gardens were transformed into very special and wondrous places where a child's imagination was acted out.
However, with television, computers, video games, organized activities and continuous fears of “stranger danger”, kids find themselves spending most of their time indoors. Recent studies have linked an increase in childhood obesity, ADD symptoms and childhood depression to this phenomenon and shown that time in nature can actually relieve some of these symptoms. One step of re-connecting kids with nature is creating and preserving meaningful nature experiences for them close to home.
Our yards have become increasingly manicured and with tidy lawns, carefully pruned shrubs and limbed up trees all designed for the adult aesthetic. By looking through a child's eye, and make a few inviting changes, yards that were once “off limits” can become an inviting place for children to explore nature-- and it doesn't have to be difficult. Instead of buying that box-store swing set a child quickly outgrows use these guidelines to create a more lasting play environment:
Let go of a perfectly tidy landscape, especially a highly manicured lawn and the chemicals it takes to make it look that way.
- Plant a diversity of shrubs, perennials and trees that will encourage wildlife including pollinators such as birds and insects.
- Stay away from poisonous plants with young children such as yew and monkshood.
- Allow “rough-edges” that are not manicured. Areas planted as a mini-prairie, wildflowers or un-mowed areas of lawn work well.
- Give children spots of their own to dig, plant, build and play.
- Instead of pre-built play houses or swing sets, give children materials to build their own. For young children create the structure's outline and let them create their own walls out of blankets or sticks; let older children build the whole thing. Forts needn't be in trees to still be magical places for kids.
- Learn to garden together. Gardening can teach skills such as patience and stewardship and build self esteem. A garden doesn't need to be big to be effective. If your neighbor has children, perhaps share a plot of ground together to also encourage team work and sharing.
- Most kids can identify exotic plants such as a Giant Sequoia or palm tree, but not the plants found in their own state such as little bluestem or oak trees. Use native plants wherever possible. These plants make better habitat for wildlife and require little maintenance.
- Add loose parts. These include sticks, branches, seeds, rocks and other objects that are movable and can be used in imaginative play.
- Use sensory plants. Children love plants that have interesting scents, textures, colors and smells.
- Use sensory plants. Children love plants that have interesting scents, textures, colors and smells.
Planting for Hummingbirds
Karma Larsen, Nebraska Statewide Arboretum
There's nothing common about a hummingbird. In size they are the smallest bird, smallest egg, smallest nest; their colors include metallic greens, blues and reds; they have the highest metabolism of any animal, with a heartbeat of well over 600 beats per minute; and they are the only group of birds that can deliberately fly backwards.
Their diet consists of flower nectar, sap from trees, spiders and insects, usually captured in or near flowers. It's been estimated that not one square meter, or 40” plot of land, goes unvisited by them in any given year. Still, they may go unnoticed until hummingbird feeders are placed to draw them more readily into focus.
Nebraska is on the migration route for four hummingbirds but only the ruby-throated hummingbird has ever been spotted in Lincoln's Pioneers Park Nature Center, and then only on its fall migration that occurs from early August into late October.
If you've never had the privilege of watching hummingbirds closely or regularly, it is well worth the time and effort to entice them into your garden. You can provide supplemental nourishment with a sugar-water mixture in a hummingbird feeder (4 parts water to 1 part sugar, boiled to remain fresh longer, NOT dyed red and changed frequently during hot weather) but the following plants will attract them into your yard and encourage them to stay longer.
As a rule, native plants contain far more nectar than cultivated hybrids. Some spring-blooming plants for their early migration in late April to mid-May include: azalea, bottlebrush buckeye, columbine, coral bells, coralberry, crabapple, currant, flowering quince, hawthorn, honeysuckle, penstemon, tuliptree and weigela.
For the fall migration that begins in early August and can run almost until frost, there are lots of options. Some of their favorites are: agastache, butterfly bush, daylily, four o'clocks, gayfeather, hibiscus, hollyhock, honeysuckle, hosta, lamb's ears, milkweed, monarda, penstemon, phlox and salvia.
Note: With the addition of a few hummingbird feeders and lots of flowering plants, we went from seeing one hummingbird a year to seeing them several times a day for several months during their fall migration. And though they are regulars now, “common” they are not!
Kentucky Coffeetree--Winter Revelations
Justin Evertson, Nebraska Statewide Arboretum
Winter - cold and gray and often foreboding. But also a good time to bundle up and get close to trees. For it is not until after the autumn drop of leaves, that the attractive bark and structural form of many trees are better revealed. One of the best trees for winter revelation is the Kentucky coffeetree ( Gymnocladus dioicus ). Native to the eastern third of Nebraska , coffeetree tells a winter story unlike any other tree.
Coffeetree has the largest leaves of any deciduous tree that grows in North America. The compound leaves, containing numerous small leaflets, can actually grow to two feet long and 18” wide. When these leaves fall, a tree of coarse texture is revealed. When young, the tree looks quite awkward and naked. In fact the scientific name Gymnocladus , means “naked branch”. But just like the ugly duckling that grew into the beautiful swan, so too does the coffeetree. Its mature winter outline is nothing short of magnificent. The plate-like bark of coffeetree is also quite attractive. In fact the low winter sun angle greatly accentuates its finer textures so that it appears almost like stucco applied to the tree.
Coffeetree is named for its hard seeds (the size and color of Milk Duds) that were roasted and ground by early settlers to create a coffee-like drink. The tree has both a male and female form and it is only on the female tree that its large but attractive seed pods are produced. The brown pods (5-7” long) typically hang on the tree through much of the winter, providing another identifying characteristic for the tree. The pods tell a fascinating story of evolution and survival. Over hundreds of thousands of years, the tree evolved with large herbivores such as rhinos, mammoths, horses and camels that long ago disappeared from the North American plain. Many of these “mega fauna” would have fed on the energy-rich seed pods in late winter and early spring. As such, the seeds had to be very hard to survive chewing and digestion so that they could sprout later in the fertile pile of the animal's dung. Although the animals long ago disappeared, the tree managed to survive to help tell us the story of a forgotten time.
Coffeetree is one of the best trees for planting in Nebraska . It is long lived, it tolerates the worst of Nebraska 's weather extremes and it will grow in a wide variety of soils. The tree also develops a nice golden-yellow early fall color. The coffeetree is one of the last trees to leaf out in the spring and one of the first to drop leaves in the fall. This evolutionary adaptation helps it avoid late-spring and early-fall freezes and also makes it very resistant to ice-storm damage. Be patient in the spring, however. Many a coffeetree has been cut down by people assuming the slumbering tree was dead.
Decorate for Christmas Naturally
Bob Henrickson , Nebraska Statewide Arboretum
ether you're creating eye-popping mantle displays, gorgeous wreaths or topiary trees, natural crafts make holiday decorating more fun. A holiday glow begins from the time you start planning your designs and gathering materials.
Make this holiday season special by creating your own natural craft ornaments for your Christmas tree, and family members of all ages can get involved. Your tree will be unique because of the materials you work with and the personal touches you add. You may even decide to grow certain plants next year specifically for crafting tree ornaments.
If you want nature inside for the holidays, it's best to begin collecting early. For the best decorations, keep your eyes open year-round for items from wooded areas, meadows or right in your own yard and garden. A large Christmas tree seems to devour small ornaments, so this is a perfect way to use up old or faded natural materials that still have some structure. You can spray paint them silver or gold to give them a warm holiday glow. Here are some fun and unique ways to bring the outdoors inside for the holidays.
Pinecones are about the easiest to collect, especially in late fall. All you need to do is fasten a small hook or paper clip into the back of the cone, tie a small bow onto the hook and hang on the tree. You can also create shimmery pinecones by spray painting them silver or gold, or adding glitter or fake snow. Cluster different cones together for variety, along with fresh evergreen branches.
Seedpods can create some beautiful decorations, and there's no limit to where you can find these. Seedpods of black-eyed susan, wild beebalm, Chinese lantern, prairie bushclover, Siberian iris, Penstemon, poppies, love-in-the-mist and milkweed are just a few examples.
Acorns: Gather different sizes and cluster them together, hold with glue (you may want to spray them with a gloss sealant), add your bow and hang. Or consider stringing them along with black walnuts or other nuts you've collected. Different varieties of nuts in the shell can be grouped and glued together and hung with a bow, or spray painted gold to add some sparkle.
Use dried flowers to create small bouquets or little nose gays . Create small bundles of dried materials, secure with floral tape or tie with raffia. Use silver king Artemisia, white statice, sweet annie, feathery dried grasses or goldenrod as backing or filler material. Dried rose buds, strawflowers, gomphrena and others can be included for a splash of color. Or glue dried flowers on small styrofoam balls to create colorful ornaments.
Osage orange or hedge apples, gathered in the fall, can be transformed into ornaments with their decorative seed patterns. Cut the large fruit into ½” thick slices, allow to dry in the oven and spray paint both sides gold. After they dry, simply insert ornament hangers and hang on the tree. Whole osage oranges, tucked into a wire egg basket, add an old-fashioned feel to the home.
Holly, bayberry, coralberry or rose hips are always a nice addition, especially if there are a lot of red berries on your sprig. A bow on the stem can be used as your hanger.
Dried fruit is a real attraction on the tree, like homemade stained glass windows. Use slices of orange, apple, pear, lemon and grapefruit. Slice your fruit 1/8” thick, dip in a solution of one part lemon concentrate and one part water, making sure the fruit is well-covered. Line several cookie sheets with brown paper bags and heat at 175 degrees for two hours, then turn fruit over and leave in oven another 1½ hours.
Pomanders are wonderfully fragrant, natural room fresheners. Oranges , kumquats, limes and lemons covered with clove studs and rolled in cinnamon and orris root or left in a bowl overflowing with spices, including bay leaves and lavender, is a definite attention getter.
In the autumn, it's not hard to find little strawberry ears of corn that can be hung in clusters on the tree with a cup hook in the back and a bow to brighten them up. You can spray paint dried okra seedpods and small gourds to complete the harvest scene.
If you have access to bark from a white birch tree , lay the bark flat on a table, use a cookie cutter and trace the shape, cut out and put a small hole in the ornament, tie a bow and hang on tree. The salmon-colored bark of river birch can also be peeled off and glued onto the sides of a tiny birdhouse made of cardboard.
Why not gather several empty bird nests and rest them on branches to finish the natural look? You may even want to add small eggs to the nest, dyed to highlight the color theme of your tree.
There are many natural beauties out there for your natural Christmas tree; and there won't be another Christmas tree like it in the whole world!
Fall Color in Shrubs
Bob Henrickson, Nebraska Statewide Arboretum
Most folks think of trees when they dream of fall color, but there are many shrubs that can put on a fantastic fall show here in Nebraska . Fall is also a great time to plant shrubs, so if you're replacing plants in your landscape or adding new ones, look for varieties with great color this time of year. G arden centers and nurseries usually have a good selection and it's the perfect opportunity to see a plant's fall color before you purchase it.
I love the way shrubs take on a whole new look as they transition from green to various hues of red, orange, yellow and purple; and often this occurs just as clusters of fall fruit are ripening also. In Nebraska , where leaves can progress from green to brown almost overnight due to fast-moving cold fronts, many shrubs known for fall color elsewhere are unreliable here, but t here are still lots of options. Some of these shrubs may not be readily available but they're worth seeking out. Many of them can grow into very large shrubs—even small trees—so provide plenty of space for them to grow into their natural shape without being pruned into meatballs!
Amelanchier , Serviceberry, provides some of the best, most reliable fall color for this region. One of the best is Shadblow serviceberry, Amelanchier canadensis , with pumpkin or red-orange color. Serviceberries typically grow in the shadow of taller trees and can be planted with other shade-loving plants to make an outstanding fall show. My favorite companion plants include the butter yellow of eastern redbud and vernal witchhazel, or the brilliant red of burning bush.
Aronia melanocarpa , Black Chokeberry , is a very reliable landscape plant in Nebraska . They can grow to 6' high with clusters of small white flowers in early spring, followed by juicy blue-black fruit for wildlife and lustrous dark green leaves. Chokeberries are tough shrubs, forming dense thickets for wildlife cover, and growing in full sun or part shade. ‘Viking' was selected for its large clusters of fruit and striking red fall color. I like ‘Autumn Magic' for its red-purple mix of colorful leaves and ‘Iroquois Beauty' for its compact 2-3' size.
Aronia arbutifolia , Red Chokeberry , is more of an upright shrub. It's somewhat open and tends to become leggy with age so it's best to plant 3' high selections like ‘Brilliantissima' in a group or mass to create a sea of red fruit and foliage. I've seen this plant struggle in hot, dry sites and in compacted construction soils with high pH. It prefers well-drained, compost-enriched soils and afternoon shade.
Corylus americana , American hazelnut, is a large, multi-stemmed, native shrub with handsome dark green leaves that I have seen change into a blend of yellow, orange and red in fall. It produces great-tasting, high calorie nuts. Most hybrid hazelnuts were selected for nut production rather than fall color and tend to have a dirty yellow fall color, so if you want fall color you may want to avoid the newer hybrids. It can be planted in full sun to light shade.
Euonymus alatus , Burning Bush. No discussion of shrubs with fall color is complete without mentioning the brilliant red of burning bush. 'Compactus' grows to about 6' tall and the cultivar 'Rudy Haag' is a 4' slow-growing variety with unique, pinkish-rose fall color. Burning bush is a tough plant that can handle a range of growing conditions, including poor soil and mild drought. An even hardier, and very similar, Nebraska native is eastern wahoo, Euonymus atropurpurea . I like it for its lime-colored twigs, fall display of pink to scarlet leaves and pink, popcorn-like fruit that dangles like ornaments after the leaves have fallen. Witchhazel is a great companion plant for either of these.
Sumacs are unrivaled for their gold, red and maroon fall colors. They tend to spread and sucker, so they are best planted in a confined space where they can form thickets. The cutleaf selection ‘Laciniata' tends to be even more spreading and suckering than other sumacs. Sumac stems can be train ed to form rustic small trees. For fall color, ‘Prairie Flame' sumac is a compact selection with rich maroon fall color; ‘Tiger Eye' has golden-yellow leaves that turn red and orange in fall; and ‘Gro-low' sumac is a popular groundcover selection growing up to 5' high with deep green leaves that turn orange-red in fall.
Viburnums. As my favorite species of shrub, I cannot list just one viburnum for fall color. Blackhaw viburnum has red to purple fall color and bluish-black fruit. American Cranberrybush viburnum, including ‘Wentworth' and ‘Spring Red,' has red fall color and bright red fruit. The arrowwood viburnum selections ‘Autumn Jazz' and ‘Red Feather' are outstanding, with a kaleidoscope blend of yellow, orange and red. Other notables include Koreanspice viburnum with wine red fall color and Burkwood with brilliant orange-red. Most viburnums are large shrubs but a number of smaller cultivars are available also.
Tree-planting for Success
By Justin Evertson,
Nebraska Statewide Arboretum
Proper planting is critical to the establishment of healthy, thriving trees. The following planting guidelines have been developed to help new trees get off to a successful start. The recommendations are based on nationally recognized standards as well as experience compiled by the Nebraska Statewide Arboretum and the Nebraska Forest Service. The recommendations assume that an appropriate tree has been selected for the planting site and that the site is suitable for planting.
DIGGING. Dig a saucer-shaped hole wider than the root system but no deeper than the root mass. Most holes do not need to be deeper than about one shovel's depth (10-14 inches). The bottom of the hole should be firm enough to prevent the tree from settling deeper after planting. Using an auger is not recommended since trees often settle too deep and the sides of the holes become glazed. If using an auger, don't drill deeper than needed and loosen the sides of the hole.
PLANTING. Plant so that the base of the trunk is at original ground level or slightly higher. The first lateral roots should end up just under the soil surface (1-2 inches deep) and the trunk should flare visibly at ground level.
-- Always locate the first main lateral roots and remove any excess soil above them before setting the plant in the hole. The first main roots are often several inches below the top of the container or root ball.
-- All graft unions should be visible above the soil line.
-- Remove all pots and containers before planting.
-- For balled and burlap (B&B) stock, try to remove the wire basket and burlap before placing the tree in the hole. If maintaining the integrity of the soil ball is important, then remove the bottom part of the burlap and wire basket before setting the plant in the hole and then remove the remaining burlap and wire basket after stabilizing the tree in the hole. Remember to check for and remove any excess soil at the top of the root ball before planting.
-- Loosen and spread circling roots before backfilling (especially important for potted trees). It may be necessary to cut larger roots that cannot be straightened to prevent girdling, but this should be done with caution. Reject plants with severely circled or girdled root systems.
-- For potted trees, try to remove as much of the original growing medium as possible before planting to help achieve good soil-root contact. Dunking in water or spraying with a hose will help in this effort.
BACKFILLING. Backfill with the original soil dug from the hole. Large clods and soil chunks should be broken up as much as possible. Adding water during backfilling can help remove air pockets and better moisten the roots.
MULCHING. Mulch individual trees with a 2-4 inch layer of wood mulch extending from the trunk to at least the drip line of the tree. Where possible, mulch trees and other plantings together en masse to help separate from surrounding turf. Don't pile the mulch deeply over roots or against the base of the trunk and don't mulch with rock or use plastic weed barriers under the mulch.
STAKING AND BRACING. Brace the tree if it might dislodge or blow over in the wind (most trees typically benefit from staking). Some sway should be allowed in the tree after staking. Use only broad, belt-like materials to attach the bracing to the trunk to help prevent rubbing injuries. Do not brace with wire, rope or wire through hose. Remove staking within one year.
Once the tree is planted, there's still work to do. Here are some tips on post-planting care:
WATERING. After planting, keep the root zone moist but not waterlogged. In general, a newly planted tree should receive about 1 inch of moisture per week, including rainwater, during the first growing season. Check the root zone frequently for moistness -- don't just guess. Many trees are lost to either under- or over-watering. Containerized trees often need more watering than bare-root or B&B stock, because the porous growing medium they are potted in dries out faster.
FERTILIZING. If the right tree was selected for the planting site, fertilizer is generally not needed. If fertilizer is desired, use only a slow-release, low-nitrogen fertilizer applied to the soil surface after planting.
-- Never add fertilizer to the planting hole since it can damage newly transplanted roots. In addition, excess nitrogen in the soil can cause newly planted trees to add top growth at the expense of proper root development.
-- Address major soil problems before planting. Adding organic matter to the planting site before planting can be very beneficial for poor, inorganic and/or compacted soils.
PRUNING. At planting time, prune only to remove dead or damaged branches and to correct structural defects. Never cut back healthy branches or trim the tree to try to "balance" the top with the roots. The tree will benefit from having as many food-producing leaves left on as possible. Also, try to leave lower branches on a tree for as along as possible after planting. Lower branches help protect the trunk from cracking, sunscald and animal damage and they aid in developing good trunk taper. If needed, limb the tree up gradually over a matter of several years after planting. Monitor the tree when young and prune, sparingly but properly, to prevent structural defects.
Asters Bloom in the Fall—Thank Goodness
Bob Henrickson, Nebraska Statewide Arboretum
For many weather-weary gardens here in the Great Plains the summer can't end soon enough. The relentless heat and humidity of July and August has taken its toll on many flowering perennials. As the summer season grows old, flower colors begin to fade and the result often is a garden full of green. If you're not ready for plain ol' green then plant some colorful asters to usher in the fall. Asters bloom late into the year—usually in September and October—with masses of daisy-like flowers in shades of pink, red, white, blue, magenta and purple.
The name aster comes from the Greek word astron, meaning “star,” referring to the shape of the flower head. The flowers not only enhance the fall garden, they produce nectar for migrating butterflies and other beneficial insects. Some asters thrive in poor dry soil and others like their feet wet. There is an aster for almost any spot in the garden, from full sun to shade.
Most asters form broad bushy clumps, so plant them at least 18” apart. Mature clumps might need to be divided every 3-4 years in the early spring, or late fall after the flowering has finished. Cut back the tops of taller selections by at least a third late spring to early summer to create a bushier plant, prolong fall bloom and keep leggy plants from flopping. This pinching should be done prior to mid-July, or it will have an opposite effect and blooming will be reduced.
The following native asters are hardy, sun-loving plants and represent some of the best for the garden. Let's begin with one of the most popular species, the moisture-loving New England Aster, Aster novae-angliae, which has furnished us with a wide variety of cultivars. 'Alma Potschke' grows 3-4' tall, with bright rosy red flowers. 'Purple Dome' grows up to 2' and, come early fall, is covered in bright purple flowers. Many asters are prone to mildew and leaf diseases and can wind up with bare legs at the base of plants. I combine my asters with ornamental grasses to help hide the legs of tall asters. The main destructive insect pest in our area seems to be the lacebug, a small grayish insect that appears in midsummer and sucks the plant juices from the undersides of leaves, primarily of the New England Aster. Leaves turn yellowish and eventually brown and fall off. Organic or synthetic insect sprays can be used for control, or try planting them in a sunny, airy open position and avoid planting them in dry, stressful areas like parking islands. Like all plants, if they are kept healthy they tend to resist attack from insects.
There are also a number of asters native to the dry prairies and rocky bluffs of the Great Plains . These drought-busters are carefree plants, growing well in hot conditions. Fragrant aster, A oblongifolius, includes the selections ‘October Skies', ‘Raydon's Favorite' and ‘Dream of Beauty,' all highly rated and easy to grow in sunny, well-drained conditions. Fendler's aster, A. fendleri, includes the white-flowering GreatPlants® selection ‘My Antonia', one of the best for rock gardens as it prefers lean, sandy soils. Upland aster , A. ptarmicoides , forms bushy plants with narrow, dark green foliage topped with creamy white flowers. Smooth aster, A. laevis, has sky blue flowers on 4' plants and the selection ‘Bluebird' has perfectly clean blue-green foliage that resists lacebug attacks.
The Woods aster series, Aster x dumosus, offers 8” dwarf asters in pink, purple and blue that are excellent for the front of the fall border. These compact selections all have clean, mildew- and rust-resistant foliage that remains attractive all season. Another tiny aster worth growing is the European native, Rhone aster, Aster sedifolius ‘Nanus' , a 12” ball of tiny sky-blue flowers.
To take full advantage of the diversity of asters—short, medium and tall, choose a worthwhile companion plant. Some of the best partners for tall asters are the late grasses like switchgrass, big bluestem and Indiangrass. I like combining the low “drought-buster” asters with shorter prairie grasses like little bluestem and blue grama.
There are many more dependable aster selections that are worth mentioning. With such a great variety to choose from, there should be at least one aster in every garden.
Milkweeds: Beauties and Beasts
Jim Locklear, Nebraska Statewide Arboretum
Some plants should be in every garden. Others should be kept out at all costs. The milkweeds qualify on both counts.
The milkweeds (genus Asclepias ) are a large group of plants, with some 120 species in the Americas and Africa . We have 17 species here in Nebraska , occurring in a wide variety of natural plant communities, including tallgrass prairie, sandhills prairie and wetlands.
Two of our native species in particular have proven their merit as garden plants, being both beautiful and well-behaved.
Butterfly milkweed ( A . tuberosa ) is the best-known and most widely-grown. A showy wildflower in its native prairie habitat, butterfly milkweed also makes an outstanding garden perennial. Its popularity is due to its prolific clusters of bright red-orange flowers which smother the rounded, 1-2' tall plants. Not only are its orange tones (sometimes ranging to yellow) uncommon among garden perennials, the flowering season of butterfly milkweed comes toward the end of the early summer rush, when many gardens are entering the doldrums. On top of all this, butterfly milkweed is a butterfly magnet, bringing even more color and animation to the garden.
Swamp milkweed ( A . incarnata ) is less commonly cultivated, but more gardeners are discovering its attributes. It has a different growth form than butterfly milkweed, with slender, willowy stems that can reach 5' in height, topped with clusters of fragrant, purplish-red flowers. As the name implies, the native habitat of swamp milkweed is wet, marshy sites, but it adapts very well to typical gardens and residential landscapes. It also is highly attractive to butterflies.
Excepting these two, the majority of our milkweeds are not recommended as garden plants, unless milkweeds are the only thing you want in your garden. Some are especially adept at taking advantage of disturbed habitat like roadsides and agricultural land, and would swamp a flower bed like Husker fans on O Street .
While most should be kept at arm's length from the garden, all of our milkweeds are worth getting to know up close in the wild. Milkweed flowers are among the wonders of the natural world, rivaled in complexity only by the orchids. As with the orchids, the pollination biology of milkweeds is fascinating, with milkweed flowers designed to snag the foot of a visiting butterfly, wasp or other insect so that it picks up a “sack” of pollen to carry to another flower.
Whether you bring them into your garden, or enjoy them in the wild, milkweeds are a beautiful and fascinating part of the rich flora of Nebraska.
Poppy mallows for the Home Garden
Bob Henrickson, Nebraska Statewide Arboretum
The poppy mallow (Callirhoe) is a genus of nine species in the mallow family, native to the prairies and grasslands of North America, that includes some familiar plants like hibiscus, hollyhock, cotton and okra. They’re beautiful plants, offering a profusion of brightly colored flowers set among deeply cut foliage.They generally start flowering in late May through June, and often continue until frost if cut back.
Poppy mallows prefer a hot, sunny, dry situation with well-drained soils. They have no serious insect or disease problems but crown rot may occur in poorly drained soils. Its root is a long-lived corm that can get as big as a turnip! They can be grown in bare areas as a ground cover or planted among prairie grasses where stems get squeezed down or weave in among other plants. They can be used in border fronts, rock gardens, wild gardens, naturalized areas or meadows. Because of their lanky nature, they are especially useful on slopes or sprawling over stone walls. Generally poppy mallows will spread in the garden, but will not root at stem nodes. Plants may self-seed in the garden in open ground or under optimum growing conditions. Long tap root gives this plant good drought-tolerance but makes transplanting of established plants difficult.
The prairie winecups or purple poppy mallow, Callirhoe involucrata, is the main species seen in gardens, but there are a fair number of other species that deserve to be planted more. I’ve grown all of following species over the years and they all have been very dependable with bright, cheerful flowers and deep green foliage that remains attractive well into the season.
Purple Poppy Mallow, Prairie Winecups, Callirhoe involucrata. A sprawling, ground-hugging plant that can cover an area up to 4’ or be planted among prairie grasses or other vertical perennials. Vibrant magenta flowers have a contrasting white eye and are particularly attractive among silver-leaved prairie plants like leadplant, Artemisia frigida or rattlesnake master. Cutting back the long stems mid-summer tidies up the plant and encourages new flowers.
Mexican Wine Cups, Callirhoe involucrata var. tenuissima, has proven to be a showy, cold-hardy plant here in the Great Plains. It blooms profusely in June with clear pink, white-eyed flowers set among very finely cut foliage. It forms a foliage mat quickly in spring, growing from a carrot-like taproop to 15” high and up to 3’ wide if given room. It demands lean, well-drained soil and is ideal for hot, sunny rock gardens, spilling over retaining walls. I like it combined with short prairie grasses like blue grama, little bluestem or prairie dropseed.
Pale Poppy Mallow, Callirhoe alcaeoides. This prairie native has more deeply cut, triangular leaves forming a fresh rosette of lacy leaves, more upright than the winecups. The selection ‘Logan Calhoun’ has showy open-faced 2” white flowers usually blooming several weeks before winecups. Growing to 18” high, it is very drought-tolerant and can take the heat. I like it combined with Echinacea pallida, ‘Prairie Smoke’ skullcap or Penstemon strictus and Missouri primrose. This prairie gem needs to be planted in full sun and well-drained soils or raised beds or it can get weak and rangy.
Fringed Poppy Mallow or Standing Winecups, Callirhoe digitata. This southern Great Plains native has finely cut, finger-like foliage and slender blue-green stems. It grows from 2-4’ high, topped with rose-red, fringed flowers in June. It prefers gowing in full sun, dry conditions and lean soils. Its naked stems and bright flowers look particularly attractive combined with Calylophus serrulatus ‘Prairie Lode’, prairie larkspur or in among little bluestem and prairie dropseed.
Bush’s Poppy Mallow, Callirhoe bushii. This species is rarely seen and is native only to portions of the Great Plains. The deep green leaves are divided into finger-like lobes, forming a bushy plant to 2’ high from a thick rootstock. The upward facing, cup-shaped bright magenta flowers bloom in midsummer, later than most poppy mallows. This plant is easily grown in somewhat dry, well-drained soils in full sun or light shade. Like all Callirhoes, good drainage is essential so avoid highly organic, moisture-retentive soils.
Return of the Elm
Justin Evertson, Nebraska Statewide Arboretum
Until the 1970s, elm trees were perhaps the most common trees planted in communities across Nebraska. American elm (Ulmus americana) was especially popular as its tall, arching habit made it an ideal shade tree for planting along streets, in parks and in back yards. In many communities the American elm comprised more than half the total species planted in public spaces. Unfortunately, Dutch elm disease spread rapidly across the state in the 1960s and 70s killing most American elms along the way and laying bare (almost overnight) the leafy canopies that once graced so many of our streets.
As a result, elms fell out of favor and are rarely planted in communities today. Fortunately, new disease-resistant varieties have been developed that can tolerate the poor soils and extreme climate of the Great Plains.
Some of the most promising elms worth trying in Nebraska include:
‘Valley Forge’ American Elm (Ulmus americana ‘Valley Forge’): One of the most disease-resistant elms, it also tolerates deicing salts, air pollution, drought, and a range of soil pH. Upright, arching habit making it an ideal street tree. 50’-70’ height and spread
Japanese Elm (Ulmus davidiana var. japonica): Glossy green leaves, relatively tight-branching and a rounded habit. 40-50’ tall by 30-40’ wide
‘Accolade’ Elm (Ulmus japonica × U. wilsoniana): One of the most promising and popular elm cultivars. 50-70’ tall and 40-60’ wide
‘Cathedral’ Elm (Ulmus davidiana var. japonica × U. pumila): A fast grower that is tolerant of clay soils, and has yellow to orange fall color. 40-50’ tall by 40-50’ wide
Lacebark Elm (Ulmus parvifolia): Attractive mottled, lacy bark develops on older stems. Leaves are smaller than most elms and deep green and very glossy. Flowering occurs in late summer with seed development in early fall. The yellowish seeds are quite attractive against the shiny green leaves. Many trees also develop a nice reddish fall color. Best adapted to the southern half of Nebraska.
‘Emerald Prairie’ is an exciting new cultivar developed in Kansas that may have better cold hardiness. 25-40’ tall by 20-35’ wide
‘Frontier’ Elm (Ulmus parvifolia × U. carpinifolia): Similar to lacebark elm, with small, glossy leaves that turn a dusty purple in the fall, and mottled bark on maturing trunks. Although some reports indicate winter dieback in the Great Plains, it has performed well in southeast Nebraska for several years. 30-40’ tall by 25-30’ wide
‘Pioneer’ Elm (Ulmus glabra × U. carpinifolia): Pioneer elm has been planted in several locations in Nebraska and has performed well in Creighton, Pierce, Waverly and Alliance, among other communities. A fast grower with dark green leaves and an upright, pyramidal habit when young. 40-50’ tall by 40-50’ wide
‘Triumph’ Elm (Ulmus ‘Morton Glossy’): Vigorous upright habit with strong branches bearing glossy, deep-green foliage. The tree appears to be very adaptable to a wide range of growing conditions. 50-60’tall by 30-40’ wide
‘Vanguard’ Elm (Ulmus davidiana var. japonica × U. pumila): Siberian elm/Japanese elm hybrid developed at the Morton Arboretum. Very tolerant of high heat and drought, making it a promising selection for the western Great Plains. 40-50’ tall by 40-50’ wide
Rock Elm (Ulmus thomasii): Native to eastern Nebraska. Its relatively narrow and upright habit is reminiscent of pin oak. A distinctive feature of this tree is the corky ridges found on stems and young branches that eventually develop into a deeply fissured bark. 50-60’high by 30-40’ wide.
Persimmons
Kristina Jensen, Nebraska Statewide Arboretum
There is a rare and fascinating tree whose native range is just outside of Nebraska . Persimmon, Diospyros virginiana . is a deciduous tree that can be found growing in dry woodlands, limestone glades, prairies, thickets, abandoned fields and along roadsides.
In spring, tiny yellow bell-shaped flowers adorn newly leafed-out branches. The foliage is dark green and glossy above, paler below. It turns buttery-yellow in autumn, infrequently reddish-purple. One to two-inch berries change from green to yellow to dark orange in color before maturing in late fall. The fruit is edible and can be rather astringent before a flavor-taming frost. Dark, alligator back-like bark maintains interest through the winter.
The persimmon has a variety of uses outside of the ornamental landscape. Its suckering growth habit can be utilized for naturalized areas and erosion control. Its fruit makes it a perfect choice for wildlife plantings and for human consumption. The pulp can be used in a variety of baked goods, syrups, jellies and ice cream. The seeds have been used as a coffee substitute; the leaves can be brewed for a tea; the flowers are useful in honey-making. A relative of ebony, persimmon wood has also been valued in the production of textile shuttles, golf club heads and parquet flooring.
Later this month, third graders in the Lower Platte South Natural Resources District will become acquainted with persimmons. As a part of Arbor Day festivities, the District will be distributing plants grown from a hardy seed source by the Nebraska Statewide Arboretum. The students will learn about persimmons in the classroom and then have the opportunity to watch them grow in their own yards.
Forcing Flowering Branches Great Way to 'Force' Spring
Bob Henrickson, Nebraska Statewide Arboretum
After another long, cold winter, it's time for some reminders that spring is just around the corner. The winter landscape can be beautiful, but it can also drag on for what seems like an eternity. The perfect remedy to chase away the dreary winter blues and bring some spring color into your home is to force some branches from your favorite spring-blooming shrubs.
Almost any shrub that blooms in early spring can be forced into bloom inside. Many ornamental trees and shrubs set their flower buds during the summer for bloom the following spring, go dormant in winter and come out to bloom when exposed to warm temperatures and moisture. Late winter, the best time to prune deciduous trees and shrubs, is also the best time to cut branches for forcing. The flower buds are generally fatter and more rounded than leaf buds.
The farther into spring you collect branches, the earlier they will open. Some woody branches will take up to three weeks to bloom, while others will flower in a week or less. No matter how long it takes, this is a great way to have a few blooms indoors while you wait for the arrival of spring.
It's best to cut branches for forcing when the outside temperature is above freezing – they will be more pliable and make a better transition from cold outdoor temperatures to warmer indoor temperatures. When you get inside, recut the stems by a few inches under running water to prevent air from being sucked into the vessels. Make sure you cut the stem at an angle to give the branch a larger surface to drink in the water.
After the branches are cut, hammer or split the cut ends, then submerge the branches in very warm water in the bathtub for about four hours to allow the buds to absorb water directly. If you want, you can stand the cuttings in a deep bucket of warm water with a plastic bag over the tops to increase the humidity overnight. The next day, you can stand the branches in fresh warm water with a floral preservative dissolved in it and put the container in a bright location. You should start forcing at 50 degrees Fahrenheit; higher temperatures at the start will blast the buds. After a couple of weeks, you can speed up flowering by moving the buds to a warm room. Check the branches frequently; they will need regular misting to prevent buds from drying out. You should also change the water every three days.
Select branches that are least 1 foot long with many enlarged buds and prune branches from all sides of the shrub to maintain symmetry. Whichever shrub you choose, make sure you cut each branch all the way to the main stem. You can always shorten the branches later if they are too long for the vase.
Pussy willow, flowering quince, and forsythia are among the most common and easiest woody plants cut for forcing. Nanking cherry, corneiliancherry dogwood, vernal witchhazel and clove currant are not as common but are very easy to force and they make excellent landscape plants as well. The spicy clove scent and rich yellow color of the clove currant will brighten any day.
Suitable branches can also be cut from other willows, wild plum, serviceberry, cherries, lilacs, flowering quinces and red maple. It's best to wait until March or perhaps April to take cuttings from harder-to-force ornamentals such as crabapple, magnolia and redbud. Late winter is also a great time to collect the bare branches of hazelnuts, alders, birches and hornbeams to force and elongate their slim, pendulous catkin flowers.
If you haven't forced spring blossoming shrubs before, make this the year and you'll be rewarded with colorful, fragrant flowers in your home.
Immediate Care for Storm-damaged Trees
Community Forestry Program,
Nebraska Forest Service
Trees damaged by storms generally require some degree of immediate attention (removal of low hanging branches, clearance from utility lines, etc). Homeowners working on their trees need to be careful to watch out for safety concerns and to consider the best approach for dealing with the tree they are trying to save. Chain saw work off the ground and other heavy work (essentially all work on large trees) should be done only by professional arborists.
Hazardous Trees. Loose or loosely attached branches and split trunks are obvious safety concerns that should be taken care of as soon as possible to avoid the possibility of injuring someone or damaging property later when the branch or that part of the tree falls. Broken but firmly attached branches that pose no immediate danger of falling can be pruned whenever convenient after the more hazardous loose branches have been removed. Trunks split down the middle are very difficult to brace adequately, and trees with split trunks should be removed or taken care of by a professional arborist.
Power Lines. Branches hanging over, or near, power lines are a major safety hazard from any standpoint. Special training is required to prune branches near power lines safely. Homeowners should never attempt to prune these branches themselves. Contact your local power company or an arborist trained in electrical line clearance to have these branches removed.
Leaning Trees. The heavy weight of snow or ice may tip a tree over by breaking some of the roots. Trees leaning from root breakage usually do not survive well. If a tree tips or develops a permanent lean in a storm, it often means the tree had damaged or poorly developed roots before the storm pushed it over. If a leaning tree does survive, it often becomes a hazard from the damage it could cause if it were to fall. Mature trees rarely survive attempts to pull them back into place after being tipped over by a storm. These generally should be removed and replaced with new trees. Very young trees (typically less than 10 years in the ground) may survive if the trees are gently pulled back to their vertical positions. If this is done, avoid additional damage to the remaining roots if possible, press out any air spaces that may have formed in the loosened soil, water the area of the root system twice each week in the absence of rain during the fall, spring, and summer, cover the root area with two to four inches of wood chip mulch, and stake the tree for the first year to prevent the tree from falling again. Do not use rope, wire, wire in garden hose, or any narrow band of material to tie around the tree during the growing season. These will injure the trunk and could kill the tree as it tries to grow. Use a broad strap or other fabric at least one inch wide and inspect and adjust the location of the strap once each week during the growing season to minimize any injury the strap might cause to the bark.
Pruning. The only pruning that should be done at this time is the removal of broken branches. Leave the fine pruning and finishing cuts until later. All pruning cuts will dry out to some degree during the winter. Take care not to leave any stubs from your pruning cuts as these will not allow the tree to heal properly. Have a trained arborist make the final pruning cuts, especially on larger mature trees. Branches that have pulled away from the trunk should be removed at the bottom of the split. Avoid causing any additional damage to the trunk. Remove any loose bark or wood fibers, but do not cut into bark that is living and still attached. Never top trees, topping creates serious hazards and dramatically shortens the life of a tree. And never use paint or wound dressing to cover wounds. These materials do no good for the tree and actually interfere with the tree's wound sealing process.
Be Conservative. Do not prune or remove more than you have to at this time. Remove hazards, but save other decisions on pruning and removals for later. While the damage may look severe at this time, concentrate more on how to can save trees rather than making quick decisions on cutting them down. Keep in mind why you wanted your trees. The trees may still be able to serve that function. Don't be too hasty to make a decision to remove a tree if you can delay that decision to the spring or even a year from now. You may decide later the tree was not damaged as badly as you thought.
For more information, go to: http://www.nfs.unl.edu/ or http://arboretum.unl.edu/.
Shrubs Help Brighten Winter Landscape
Christina Hoyt, Nebraska Statewide Arboretum
How can we brighten up the winter landscape? One way is by incorporating evergreen and semi-evergreen shrubs into plantings. Evergreen shrubs are not restricted to yew, boxwood, arborvitae and juniper but extend to include cotoneaster, viburnum, rhododendron, bayberry and many of the dwarf pines and spruces.
This time of year, many winter arrangements feature pine boughs and holly leaves. For centuries Europeans have been using hollies to dress up their winter landscapes, indoor and out, so it seems fitting to take a look at holly and holly-look-a-likes we can use in our region.
Hybrid Holly -- (Ilex x meserveae) The most commonly grown holly in this region. It has spiny, lustrous leaves that are a deep beautiful green. Hollies require both male and female plants for production of the coveted red berries. A reputable nursery should be able to assist with choosing compatible male and female cultivars. Desiccation in winter winds and sun scald in the summer can be a problem so hollies need a protected location. North and easterly exposures work particularly well for growing hollies in our climate. Many hybrids are available, some faring better in winter than others, so pick one that is appropriate for where you live.
American Holly -- (Ilex opaca) This is a holly for the plant collector that wants a challenge. It needs moist acidic soils and protection from excessive winds. The form is distinctly pyramidal and approaches 30 feet tall in its native region of the southeastern US. Zone 5.
Oregon grapeholly -- (Mahonia aquifolium) Leaves are similar to Ilex in the sense that they are a spiny, lustrous dark green; however, Oregon grapeholly has compound leaves and gets a lovely purple hue in winter. This shrub has a rather expressive form, sometimes squat and dense and other times more irregular and open. In spring it is adorned with bright yellow flowers followed by persistent dark-blue berries in the autumn. Growing 3 feet high and wide, it is perfect for smaller more protected locations. Give it some shade. Native to the northwestern region of the United States. Zone 5-6.
Creeping mahonia -- (Mahonia repens) Native to Nebraska's Pine Ridge and the Black Hills, this is our version of Oregon grapeholly. Similar to its cousin in appearance, with slightly duller leaves, its outstanding fall color surpasses that of Oregon grapeholly. It only grows 10-18 inches high and has a gently creeping habit. Yellow flowers dress it up in the spring and black fruits in late summer. Once it is established it is extremely drought tolerant. It should be used more throughout Nebraska especially in droughty situations and western Nebraska landscapes. Zone 4.
Have a Berry Christmas!
Karma Larsen
The leaves almost need to disappear before we notice them but suddenly, just in time for Christmas, they’re everywhere—berries. We’ve been paying attention to the changing, falling leaves and, without our noticing, the stage has been reset. While we’ve been busy putting up trees and wreathes and garlands, Nature has done its own decorating.
Fortunately for birds, the plants we add to our gardens for winter beauty are often the very plants they need to get them through a long, sparse winter. Placing a few shrubs and small trees near to a birdfeeder will make it a much more appealing site, protecting them from wind and predators and adding variety to their diet.
As a gift to yourself and to all the birds in your neighborhood, here are some great additions to the landscape:
Eastern wahoo, Euonymus atropurpurea. This native 10-12’ shrub bears abundant, beautiful rosy-pink seed capsules that stand out vividly in late fall. A hardy, drought-tolerant shrub that is beautiful year-round but especially dramatic this time of year.
Wax myrtle, Myrica pensylvanica. The birds may devour these waxy, gray berries before you get to enjoy them, but Myrica also has semi-evergreen, fragrant foliage. It’s a tough, deer-resistant shrub for dry, infertile sites that can help prevent erosion and build up nitrogen.
Coralberry or snowberry, Symphoricarpos. Though not a first choice of birds, these persistent white and purplish-red berries are beautiful through the winter.
Viburnums. There’s no end to the options here. The bluish-black berries of blackhaw viburnum (Viburnum prunifolium) are a good source of food for birds in fall. For persistent fruits later in the winter, there’s American cranberrybush viburnum (Viburnum trilobum) with fruits that become more palatable as the winter progresses, making it a good choice for late winter feeding. Linden and sargent viburnum (V. dilatatum and sargentii) are other good choices for persistent fruit.
Perennials for Fall Color
Kristina Jensen
Fall is a time to notice the surrounding landscapes. We can't help but notice trees and shrubs turning brilliant shades of yellow, orange and red. But they're not the only plants to have fall color; perennials are preparing for a long winter's nap, too.
Bluestar, Amsonia . Dark green, willowy foliage is sprinkled with tiny blue flowers in spring. By fall, this plant becomes a firecracker in the garden with bold, golden foliage.
Solomon's seal, Polygonatum . A wonderful addition to the shade garden, Solomon's seal has pendulous white flowers in spring that become bluish-black berries in summer. The fruit, paired with yellow fall color, makes an attractive combination. Variegatum', with its ivory-streaked foliage, is especially nice.
Other perennials for yellow fall color:
Gooseneck loosestrife ( Lysimachia clethroides ), monkshood ( Aconitum ), hosta, balloonflower ( Platycodon ), ferns.
Bloody cranesbill, Geranium sanguineum . With a name like bloody cranesbill, it should be no surprise that the finely textured foliage of this perennial turns crimson in the fall.
Cushion spurge, Euphorbia polychrome . In spring, this spurge is topped with sulfur-yellow bracts. In autumn, it becomes stained in shades of red and orange.
For red fall color, try these perennials: columbine ( Aquilegia ), pigsqueak ( Bergenia ), plumbago ( Ceratostigma plumbaginoides ), barrenwort ( Epimedium ), prairie alumroot ( Heuchera richardsonii ), peonies ( Paeonia )
For grasses, try:
Autumn Red Miscanthus, Miscanthus sinensis var. purpurascens ‘Autumn Red'. The early-blooming silvery plumes of this grass look great against orangish-red fall color. Interest remains throughout winter.
Little bluestem, Schizachyrium scoparium . A native bunchgrass with blue-green summer foliage turning various shades of red and bronze and topped with fluffy seedheads in the fall.
Other notable grasses: switchgrass ( Panicum ), Indiangrass ( Sorghastrum nutans )
And a vine for fall, too… Virginia creeper, Parthenocissus quinquefolia , A fast-growing vine and considered a weed by some, virginia creeper can't be beat with a vibrant rainbow of fall color.
Botanical Bits September 2006
Sizzlin' Summer Silphiums & Sunflowers
By Bob Henrickson
Having trampled through many prairies in eastern Nebraska , I have become very familiar with the big burly plants from the genus Silphium , also known as rosinweeds. In the prairie, these tall, bold-textured plants with bright yellow sunflower-like blossoms take center stage in late summer, a focal center among a sea of grasses. In the garden, these impressive, deep-rooted plants make a dramatic and pleasing addition to the back of a mixed border. The tall, stiff flower stalks add an interesting vertical element to the garden and the big leaves add contrast and weight to fine-textured grasses. On the prairie “plant calendar” the Silphium blossom is a sign that summer is almost over, while the sunflower or Helianthus blossom ushers in the fall.
The name sunflower refers to their habit of facing the sun from sunrise to sunset. Most of us are familiar with the common annual sunflower growing along field margins and roadsides, but the perennial sunflowers are also important prairie forbs. Ripening in fall, the seeds are ready just in time for migrating birds to gorge on as they make their way south.
In the flower garden these beauties spread rapidly by rhizomes to form impressive colonies. Sunflowers work best either competing with equally aggressive prairie plants like big bluestem and Indiangrass to keep them in check, or planted in an island surrounded by mowed grass. They're very drought-tolerant and able to break through heavy soils; but if the soil is too rich or they get too much water they will flop over when blooming.
If you're looking for a classic, tough prairie plant to add some color late in the season, find a place in your sunny border for these bold beauties.
Compass plant, Silphium laciniatum. The deeply cut, rough, leathery leaves of compass plant can grow up to 20” long, like a giant oak leaf. Mature plants send up a massive flower stalk that can reach up to 10', with clusters of large yellow flowers along the stem. Prairie grasses like little bluestem and prairie dropseed make nice, fine-textured companions to the big leaves. Most Silphiums need at least three years to mature but will reward you by living for decades.
Rosinweed, Silphium integrifolium. The dark green, thick leaves of rosinweed, stiff and rough to the touch, are a nice complement to the bright yellow flowers clustered at the top of the stems. A mature plant will give rise to many stout, erect stems that may reach 5' high and 3' wide. A dependable performer and one of the best-behaved for the garden, growing well in a variety of soils from moist to dry and excellent in clay. Try as a backdrop for other perennials or grasses.
Downy sunflower, Helianthus mollis. Beautiful butter-yellow flowers, blooming in August, complement the soft, grayish-green leaves. Growing up to 6' tall, this species is also called ashy sunflower because the fuzzy leaves look like they've been rubbed in ashes. Creeps slowly by rhizomes, making this one of the best-behaved of the sunflowers. It prefers dry, well-drained soils.
*The following natives are aggressive and best limited to prairie gardens; they are not recommended for home garden usage.
* Cup plant, Silphium perfoliatum . According to Neil Diboll of Prairie Nursery, “the cup plant is the single best species that you can plant for wildlife.” The bright yellow flowers are a favorite of butterflies and it ranks as the number one plant for birds, providing food (birds devour the nutritious seeds in fall), water (leaves clasp the square stems to form little cups that can hold rainwater) and the large foliage also provides cover. Give it plenty of room, because this big boy can grow up to 8' high and it self-seeds readily in open soil.
*Common sunflower, Helianthus annuus. This species is the wild-growing ancestor of the commercially grown sunflower. It was reportedly cultivated by American Indians who selected for plants with large seeds.
*Sawtooth sunflower, Helianthus grossererratus. This sunflower is very vigorous, forming large, robust colonies. It can be recognized by its coarsely toothed leaves and large clusters of bright yellow 2-3” flowers. This species grows naturally in rich bottomlands and wet prairies.
*Maximilian sunflower, Helianthus maximilliani. This impressive sunflower has bluish-green, sickle-shaped leaves folded into a trough shape and arched. In late summer stout stems may reach over 6' high, with big yellow flowers along the top 3' of stem. The stiff stems serve as perches for seed-eating songbirds in fall. Very aggressive.
*Prairie sunflower, Helianthus pauciflorus or H. rigidus . This widespread species is also called stiff sunflower in reference to its stout, erect stems. The blossoms, occurring singly at the tip of the central stem flower, are about 2½–4" across and have dark red centers. It grows to 6' high. Easy to grow, but can spread and become very aggressive.
*Jerusalem-Artichoke, Helianthus tuberosus . This sunflower is neither from Jerusalem nor an artichoke. It is a perennial sunflower that produces tubers 3-5” long that have a sweet nutty flavor. Cultivated for centuries, the “earth apple” has large coarse leaves, rough leafy stems and clusters of bright yellow flowers in fall. Very aggressive and can take over an area if left undisturbed.
* More information on sunflowers, including “The Sunflower Project,” an arts and interdisciplinary curriculum for classroom usage, can be found at arboretum.unl.edu. Funded in part by the Nebraska Arts Council, the curriculum packets will be mailed to Nebraska high schools this month.
Botanical Bits – August 2006
Dealing with Drought
By Justin Evertson
Drought—“a prolonged period of dry weather” ( Webster's New World College Dictionary )
In Nebraska , drought is not at all unusual. Historical records and tree ring studies clearly show that drought is a normal part of the Great Plains environment. Most of Nebraska suffers from drought conditions once every seven years. What is most frustrating for everyone choosing to live on the plains is that droughts are unpredictable.
As dry as it is, however, I actually am impressed at the appearance of Nebraska 's community landscapes. A closer look reveals trees, shrubs and herbaceous plants that are suffering and dying. But for as dry as it has been, the decline is not nearly as pronounced as one might expect. It's understandable to see green plants on irrigated sites, but where are non-irrigated plants finding the moisture to keep photosynthesis going?
To me, the plants that look the best this year are either native to the region or are native to similar climates elsewhere in the world. A few of the woody plants that continue to thrive include bur oak, hackberry, boxelder maple, coffeetree, American plum, chokecherry, coralberry, mountain mahogany, ponderosa pine, blue spruce and juniper. Our prairie forbs and grasses may not be growing robustly or flowering profusely, but they are surviving and will no doubt thrill us again when the rains return.
In a year with little or no rain, maintaining landscapes in a lush condition can seem like an impossible challenge—and rightly so. The need to conserve water and wisely budget maintenance time should be paramount in any caregiver's decision-making process. And yet as daunting as the task may seem, it should not be impossible to at least keep the most important components of a landscape alive so that they are ready to thrive when the rains return.
Perhaps the most important task to be accomplished when managing for drought is to prioritize both landscape components and maintenance needs. I don't hesitate to proclaim that trees are the most valuable part of the landscape, followed by shrubs, perennial flowers and grasses, annual plantings and finally turf grass. This assessment is based purely on the reality that in the long run trees and shrubs provide the biggest benefit to a community. In addition to the shade and wind protection that woody plants provide, estimates show that trees already save over $1 billion in utility costs each year in Nebraska . Where would we be without our woody friends?
Unfortunately in this society, turfgrass development and care seems to remain the most important landscape activity. Precious water is dumped on the lawn in a futile effort to keep it green in the heat of summer. For a typical suburban residence with automatic lawn irrigation, it is not uncommon to see water use increase nearly five-fold during the summer.
Although turfgrass does provide many important benefits to the community (reduced erosion, cooling effect, places for play, pleasing look, etc.), I'm not convinced the tangible benefits of keeping it green during dry times exceed the costs. We should not mourn for the browning of turfgrass during a drought. The reality is that turfgrass is easily reestablished when the temperature cools and the rains return. A tree, on the other hand, takes several years to be securely established in the landscape and to begin providing its amazing benefits. For such plants, a drought can quickly wreck an amazing investment for the future.
With all that in mind, here's a few maintenance tips to consider for periods of drought:
1. Prioritize the landscape to insure the most important plants are kept alive.
2. Prepare during wetter periods for the dry times to come.
3. Let turfgrasses go dormant in the heat of the summer.
4. Trees, shrubs and herbaceous plantings should be watered deeply and infrequently. Trees and shrubs planted in the spring will need approximately one inch of water per week during the summer. Plants established in previous years may need only one or two waterings per month to get through a severe drought. Water trees at the drip line if possible.
5. Recognize the needs of individual plant species. An established bur oak requires much less moisture, for example, than a red maple or tuliptree.
6. Reduce watering in late summer. Most woody plants naturally begin shutting down their growth processes at that time and will require less moisture to survive.
Irregardless of maintenance capabilities and priorities, the best thing to do to help manage for drought is to plan and develop landscapes from the outset that are able to tolerate the climatic conditions that will come. Species selection and proper placement in the landscape are vital to this effort. For years, ecologists and environmentally conscious designers have been promoting the benefits of native and well-adapted plants that will naturally thrive in the environments they are placed in. If nothing else, a drought year like this helps prove how wise such proclamations are.
Botanical Bits – July 2006
Community Tree Forest
By Christina Hoyt
Nebraska is the “Home of Arbor Day” and, as that implies, Nebraskans are tree planters, dotting our prairie state with trees that give us shade and shelter through the year. Walking through our communities, it's easy to take trees for granted and forget our role in planting and caring for them for generations to come. There are many lessons we can take from our tree-planting forefathers… plant correctly, plant for the future and plant diversely.
J. Sterling Morton, founder of Arbor Day, planted a great diversity of trees, most of which can still be seen at Arbor Farm Historical Park in Nebraska City . It's amazing to see these majestic old trees, and many of them are species that rarely find their way into our landscapes today.
Nowadays, our community forests are far less diverse than they should be, increasing the risk of losing them to diseases or pests. Not only do we need diversity, we also need tough trees. For a tree to be successful in the greater part of Nebraska it needs to survive drought, wind and temperature fluctuations. Here are some underutilized, tough trees that should find their way into our landscapes more.
Ironwood, Ostrya virginiana , is a native to southeastern Nebraska woodlands found predominantly in bur-hickory forests in the upland areas. It is very drought-tolerant and can withstand “tree pit” conditions also, but it prefers the protection of an overstory tree. Beautiful “hops” set on in June, making it look like a well-decorated Christmas tree and foliage turns yellow in fall.
Miyabe maple, Acer miyabe , is native to Japan . It is incredibly durable, and should be a first choice among maples for our state. Like most maples it prefers moist conditions, but holds up under the rigors of drought. It has an oval-rounded canopy, growing 30-40' tall and has pumpkin yellow fall color.
Gambel oak, Quercus gambelli, is native to Colorado . It can be used as a large shrub; single-stemmed, it forms a medium-sized tree. It can withstand the rigors of wind and drought and is an excellent tree for acreages and in windbreaks, especially in central and western Nebraska .
Ussurian Pear, Pyrus ussuriensis , is native to Asia . It does well with temperature fluctuations, drought and some wind, making it a much better choice than Bradford pear. It works well throughout Nebraska and has white flowers in spring and red-purple leaves in fall. Grows 25-30' high.
Bristlecone Pine, Pinus aristata, is native to the southwestern United States . Some of the oldest living trees on earth—4,000-5,000 years old—are bristlecone pines. Though slowrowing, it can handle drought and severe winds and performs well in both eastern and western Nebraska . Amur Corktree, Phellodendron amurense, is an underutilized medium-sized shade tree. Its deeply furrowed bark gives it a corky appearance. The tree is diocius, having both male and female trees; male trees tend to be more picturesque with large branches that sweep the ground. begging to be climbed.
Botanical Bits – June 2006
Wildflowers
By Bob Henrickson
The first annual Nebraska Wildflower Week will be observed from June 3-11, 2006! Typically, this is one of the best times of the year to walk through a prairie, with colorful wildflowers swimming among a sea of fine, abundant grasses. The prairie garden is in its prime too, with lush, green grass and abundant flowers in bloom. You may be surprised to learn that some of the most beautiful flowers you can grow in your garden make their home right here in the Great Plains . I have been growing Nebraska wildflowers for years and I'm amazed by the array of outstanding spring wildflowers that have found their way into my gardens. Like most home gardeners I strive to include a plant palette that provides color from spring to frost and to my delight, there are native wildflowers in bloom from early April to late October.
In learning more about wildflowers and prairie grasses I was surprised to learn of the many spring-blooming varieties. I assumed that most wildflowers bloomed in the late summer and fall, with the asters and sunflowers. But there are some dazzling plants waiting to be discovered and planted in your garden that bloom in late spring through early summer.
The following is a list of native wildflowers representing just a few of the many varieties available for late spring color. Not only are they showy, all of these sun- and heat-loving plants are very drought-tolerant and thrive when planted in well-drained soils.
Shell-leaf Penstemon ( Penstemon grandiflorus )
The blue green leaves of this durable perennial are thick and fleshy forming an attractive clump the first year and giving rise to erect, stout 3' high stems the second season. The stem leaves are evenly spaced along the stem, nearly round, clasping the stems like a clam shell. The abundant, tubular flowers rest among the leaves and bloom an incredible lavender color. Soon showy seed heads develop, turning a rich brown color in fall and remaining attractive well into winter.
Prairie Phlox ( Phlox pilosa ) The beauty was once a common wildflower in the moist, rich soils of low prairies in eastern Nebraska . This native perennial, with grass-like leaves and erect stems from 1 to 2 feet high, has been very dependable in the garden. The fragrant, deep pink flowers are in clusters at the end of the stems, blooming from late May into June. I have mine combined with the bright yellow lanceleaf coreopsis (Coreopsis lanceolata) and prairie spiderwort ( Tradescantia ohioensis ) for a delicious prairie garden combination.
Pale Purple Coneflower ( Echinacea pallida ) The native purple coneflower blooms by early June in my garden and continue for a month. The flower heads have pale pink drooping petals around a dark red, domed shaped disk. The flower petals seem to dance in the slightest breeze while resting atop stout, unbranched stems to 3' high. The stems and long, linear leaves are covered with stiff hairs. The seed heads of this species remain tight well into winter and are ideal for winter interest among prairie grasses. I have mine combined with leadplant and butterfly milkweed, prairie dropseed and little bluestem for a no fuss combination.
Leadplant ( Amorpha canescens ) This attractive, long-lived woody perennial belongs in every sun drenched garden. The woody stems have silvery-green foliage, densely covered with short, whitish hairs, and give rise to a deep blue flower stalk in late spring. The spike-like stalks are dusted with golden anthers and although fleeting, are incredibly showy. The plant may take several years to get establish and I cut to woody stems back to around a foot in the spring. Leadplant will grow from 2-3 feet high and wide and compliments any sun-loving native.
Prairie Skullcap ( Scutelleria resinosa ) I love everything about this showy wildflower. It has grayish-green rounded leaves, like mouse ears forming a rounded 12” plant by late May. Within the margins of the leaves are deep blue rounded flowers, each tipped with two small white patches, like an equal sign. The effect of the grayish leaves and the indigo blue flowers is a striking combination magnified when planted next to the native toothed primrose ( Calylophus serrulatus ), fringed sage ( Artemisia frigida ) and New Jersey tea ( Ceanothu s americanus )
Sensitive Briar ( Schrankia nuttallii ) A native perennial with attractive fern-like foliage that are touch sensitive like the mimosa. The 1-3' stems are weak, sprawling along the ground or aloud to weave in among shorter prairie grasses. In late spring numerous rounded flower heads appear at the tips of the branches. The rich pink heads look like miniature sputnik satellites, each up to an inch across, tipped with yellow anthers. This plant grows best in dry, well-drained soils and I have mine combined with dwarf blue indigo (Baptisia minor), wild larkspur (Delphinium virescens), and cobea penstemon (Penstemon cobea).
Botanical Bits – May 2006
Spare the Dandelion
By Justin Evertson
This spring, before rushing out to attack any dandelions that may have emerged in the lawn, do your trees and shrubs a favor and put away the herbicide. Dandelions typically emerge in mid-to late spring at about the same time many woody plants are unfurling their first tender leaves. Unfortunately, most common herbicides used to kill dandelions in the lawn can have significant negative impacts on trees and shrubs. This is especially true in the spring when winds are frequent and the tender new growth of woody plants is most susceptible to herbicide drift. Oaks, maples, redbuds and nut trees seem to be especially vulnerable to herbicide drift. A sure sign of herbicide damage is unusual leaf curling along with stunted leaves, early in the season.
Most healthy trees and shrubs can tolerate some light and occasional herbicide drifting. Contact repeated year after year, however, can cause serious decline and even death to vulnerable plants. The better time of year for herbicide treatments of dandelions and other perennial lawn weeds is in the fall when trees and shrubs are not actively growing and are thus less susceptible to herbicide drift. In addition perennial weeds will translocate more of an herbicide to their root system in the fall as they actively move energy below ground for winter survival. This greatly increases the chance that an herbicide will kill the entire weed. Something else to consider: dandelion leaves can make a cheap and tasty addition to any garden salad. So instead of poisoning them, consider eating them instead. That is sweet revenge!
Botanical Bits April 2006
Native Shrub Brightens Spring Landscape
By Kristina Jensen, Nebraska Statewide Arboretum Nursery Technician
Spring is the time of year when one of our native shrubs really shines. Clusters of white flowers cover the branches of Amelanchier even before the leaves emerge. Amelanchier has several common names, among them “serviceberry,” since in pioneer time it was often the only plant blooming for spring burials, and “Juneberry” for the blueberry-like fruits that follow in June.
The fruits appear reddish, then turn dark blue-black when ripened. They are edible to wildlife and people alike. Native Americans had many uses for the fruit, whether eaten fresh, in stews, or combined with meats in pemmican. Early North American settlers also utilized the tasty pomes, similar in taste and appearance to blueberries, for making pies, wines, jams and other fruit concoctions. These uses are regaining popularity, partially because juneberries have been found to be higher in protein, calcium, fiber and many other nutrients than either blueberries or strawberries. Scientists in Canada are working to select large-fruited cultivars for commercial purposes.
Over 25 species of Amelanchier exist in the Northern Hemisphere. Among these species, three are native to the state of Nebraska.
Saskatoon serviceberry ( A . alnifolia ) is found in northern Nebraska and reaches into central parts of the state. It grows up to 15' high along streambanks and hillsides. ‘Regent' is a well-known hybrid with a dense, suckering habit.
Shadblow serviceberry ( A . arborea ) is an understory tree found in the woodlands along the Missouri River. Often multi-stemmed, this serviceberry grows up to 25' high. It prefers moist, well-drained soils, but will tolerate poorer conditions. ‘Robin Hill' is a pink-flowering hybrid.
Dwarf serviceberry ( A . sanguinea ) is a 10' high shrub native to the northwestern corner of the state. Red twigs accent this colony-forming serviceberry that is not common in the nursery trade.
Later this month, third graders in the Lower Platte South Natural Resources District will become acquainted with serviceberries. As a part of Arbor Day festivities, the District will be distributing plants grown from a hardy seed source by the Nebraska Statewide Arboretum. The students will learn about serviceberries in the classroom and then have the opportunity to watch them grow in their own yards.
For photos, planting and other information about serviceberry, go to arboretum.unl.edu/poppages/serviceberry.
Great Trees for Small Landscapes
By Don and Jan Riggenbach, Freelance Writers and Plant Lovers
No matter how small your yard or how fully-planted you might think it is, you probably have room for at least one more tree. Maybe not a giant oak, but most yards can still accommodate another small ornamental tree, or one of the delightful understory trees that are native, or adapted, to our Midwestern landscapes.
During the first 15 years we lived on our acreage we enjoyed the native woodlands that surround a ravine on the property. But we wanted a lot more variety, height, shade and structure in our landscape so we began planting species and cultivars of native and introduced, non-invasive trees and shrubs about 15 years ago. Our collection has grown to several hundred and we love them all, but here are a “delightful dozen” that rank among our favorites.
Shantung maple ( Acer truncatum) . This is a terrific small maple, whose leaves turn a beautiful reddish-orange in fall. Our specimen was damaged by the October 1997 snowstorm, but with a little pruning quickly recovered its oval shape. It does best in full sun but can take a little shade and still produce fall color.
Trident maple ( Acer buergerianum ). Even visitors who profess no interest in trees seem to notice the dainty, 3-lobed leaves and muscly trunk of this delightful small maple. The dark green leaves turn a brilliant red every fall, and our two specimens have shrugged off some major snow and ice storms.
American hornbeam ( Carpinus caroliniana ). “Musclewood” is a small, adaptable, understory tree with few insect or disease problems and nice orange-red fall color. It's perfect for filling the gap between grass or groundcovers and the crowns of bigger shade trees.
Katsuratree ( Cercidiphyllum japonicum ). Our 13-year-old katsura towers 35' above a pathway behind the house. Its rounded leaves—red-tinged in spring, blue-green in summer and yellow in the fall—never fail to attract visitors' interest. We like it so much we've planted two more.
White fringetree ( Chionanthus virginicus ). This tiny, slow-growing tree, which thrives in either partial shade or full sun, rewards us with a spectacular flower show every spring. A friend gave us the 1917 book Trees Worth Knowing , which says, “Whoever goes into the woods in May is rewarded for many miles of tramping if he comes upon a ‘snow-flower tree' (fringetree) in the height of its blooming season…an experience that will not be forgotten.” Fortunately, you can grow one at home and save the tramping.
American yellowwood ( Cladrastis lutea ). This handsome, low-branching, rounded tree is mid-sized. We like its spring show of lacy white flowers, although ours often takes a year off between peak performances. Its bright green leaves provide a nice contrast to the darker leaves of oaks and maples.
Seven-son flower ( Heptacodium miconioides ). This unusual small tree provides a late summer show of 6-inch-long clusters of creamy-white flowers. After the petals fall, the sepals turn rosy-red, producing a stunning flowering effect that lasts until Thanksgiving. Seven-son has handsome, peeling bark that resembles that of a crapemyrtle.
Dawn redwood ( Metasequoia glyptostroboides ). Dawn redwood's delightful, feathery, bright-green leaves change to rich, reddish-brown in the fall. It's a deciduous conifer from Asia, once thought to be extinct, and grows fairly rapidly into a huge, pyramidal tree. Ours flourishes in a low, wet, open spot.
American hophornbeam ( Ostrya virginiana ). Happy in either full sun or as an understory tree, “ironwood” has elm-shaped leaves and showy spring flowers. In his Manual of Woody Landscape Plants , Michael Dirr writes that its autumn color is seldom effective and the leaves fall early. That has not been the case for our hophornbeams. Instead, the leaves turn from yellow to rusty brown, hanging on most of the winter. We love the greenish-white fruits that resemble hops, too.
Mongolian oak ( Quercus mongolica ). We'd grow this one for its bright red fall color alone, although its dark-green summer foliage is eye-pleasing, too. Our two specimens are low-branching with a full, oval shape and no problems.
Common sassafras ( Sassafras albidum ). A pleasure in all four seasons, sassafras has bright yellow early-spring flowers and multi-shaped leaves that are bright green in summer, changing to orange, red and purple in fall. The bark is a dark reddish brown, very handsome in winter. Although suckering can occur, ours has remained a handsome, single-stemmed tree and has yet to produce a single sucker.
Lacebark elm ( Ulmus parvifolia ). This is the real Chinese elm, not to be confused with the weedy, breakage-prone Siberian elms that are often mistakenly called Chinese. The lacebark has, as its name suggests, beautiful bark. It also has small, glossy-green leaves and is highly resistant to Dutch elm disease. Two great cultivars are ‘Glory' and ‘Hallelujah' from Arbor Village Nursery in Holt, Missouri.
Designing with foliage by Christina Hoyt
Though foliage characteristics are often neglected in favor of showy flowers or fruit when choosing a plant, gardeners have begun to realize what a significant role foliage can play in the garden. As a result there are some elegant, striking, and even gaudy, plants showing up at garden centers.
Color and texture are two of the most important foliage characteristics. Color, particularly, tends to catch our attention. Whether it's chartreuse, purple, blue, variegated or mottled, brightly colored foliage offers a very striking accent in the landscape. Generally, plants with more vibrant foliage are reserved for specimens or for brightening dark corners. Rarely are they used extensively as a backdrop for the garden.
Unfortunately, many diseased plants are similar in coloring to chartreuse, yellow or variegated plants; which makes the line between looking “sickly” and “stunning” easy to cross. When experimenting with extreme color it's best to start with annuals or perennials. Mistakes will reveal themselves more quickly and it's easier to move or replace a small plant than a 15-year-old shrub. Keep in mind that green is a color too; use solid green foliage generously and other color sparingly.
Variations of grey and silver foliage occur naturally in drier parts of the country. They combine well with many shades of green and can be used in masses, making them very versatile in a landscape design. Gardens featuring silver and grey-toned plants are attractive and calming, and can offer a bright spot in the evening hours.
Texture is another important component of designing with foliage. Offering a combination of textures can create variety in the garden, and a subtle contrast of texture is much more forgiving than the contrast of different colors. When viewed from a distance, the size of the leaves affects the “texture” of the design, with large leaves giving a coarse appearance and small foliage resulting in a fine-textured appearance. Using a variety of textures, fine-textured grasses alongside medium-textured roses, for instance, can add a lot of interest to the landscape. For drama, the large leaves of an oakleaf hydrangea can be paired with coralberry or fine-textured grasses. Varying, contrasting and repeating leaf types can make a pleasing, coherent design. Nature offers an infinite variety of leaf shapes (oval, heart-shaped, narrow) and leaf surfaces (fuzzy, rough, puckered, sharp or shiny) that give plants personality. The soft foliage of lamb's ear, for example, is almost irresistible not to stroke. Shiny-leaved plants catch the sunlight and contrast nicely with duller leaves. Cactus leaves add an unexpected prickle while keeping the wary pedestrian at bay.
As with any good design, less is more. Pick a few plants to add boldness and contrast, and let the rest of the garden offer subtle repetitions and variations of a similar theme. Experimenting with foliage is a fun and easy way to enliven your garden!
Botanical Bits January 2006, Warming Winter with Native Pines by Justin Evertson
During winter, when the coldest winds blow, many Nebraskans find themselves wondering why they live here. This is especially true du