The affiliate sites of NSA can be many things: an outdoor classroom, a place for play or reflection, a laboratory to test new plants, a stage for the performing arts, but they are all places where plants are displayed for their aesthetic, educational, historical or cultural value.

The following are categories of affiliated sites of the Nebraska Statewide Arboretum.

• Accredited Arboretum - a planned and curated collection of plants assembled to accomplish an identified educational mission
• Historic Landmark - a planned landscape of historic or cultural significance to the state of Nebraska
• Landscape Steward - a public landscape that demonstrates an ongoing commitment to excellence in design, plant diversity and maintenance