Collections and gardens

Plant collections by region

With more than 17,000 plants representing over 2,400 species and cultivars, U of I's Arboretum and Botanical Garden is home to one of the most diverse outdoor plant collections in the Inland Northwest.

Most trees and shrubs in the Arboretum are grouped by their geographic origin. Currently, there are four regional collections in the Arboretum. Each area showcases species native to its region, offering a global botanical experience in one scenic location.

  • Asia
  • Europe
  • Eastern North America
  • Western North America

You’ll also find rare and striking specimens throughout the Arboretum, including:

  • Dawn Redwood (Metasequoia glyptostroboides)
  • Ginkgo (Ginkgo biloba)
  • Camperdownii Weeping Elm (Ulmus glabra 'Camperdownii')
  • Giant Sequoia (Sequoiadendron giganteum)
  • European Beech cultivars (Fagus sylvatica)

Memorial trees, groves and benches

The Arboretum features 165 memorial trees, groves and benches honoring individuals and groups. Locations can be found on the Arboretum map (PDF) using the grid location indexes provided on the page.

Display gardens

Located at the south end of the Arboretum, the display gardens showcase plants grouped by type or landscape use. Highlights include:

  • Xeriscape Garden — low water-use landscaping
  • Ornamental Willows
  • Daylily Garden — a national display garden with the American Hemerocallis Society
  • Iris Garden
  • Heather Garden
  • Butterfly Garden
  • Hosta Garden — nationally recognized by the American Hosta Society (in the Asian section)

The Charles Houston Shattuck Arboretum collection

Located just west of the Administration Building, the Shattuck Arboretum is one of the oldest university arboretums in the Western U.S. This 14-acre site was created in 1910 when Charles Shattuck, founder of the university’s forestry program, planted hundreds of trees and shrubs to transform a weedy hillside into a living classroom. Named in his honor in 1933, the Shattuck Arboretum remains a beautiful, historic space for education and reflection. The adjacent amphitheater provides a scenic setting for events including lectures, concerts, weddings and more.  

The Shattuck Arboretum is home to mature trees such as American Beech, English Maple and California Incense-Cedar. One of its most iconic features is a Giant Sequoia planted in 1916, still standing tall today.

Explore the Shattuck Arboretum (PDF)

Commemorative tree, grove and bench indexes

Arboretum plant populations and inventory

Spring highlights

Spring flowering trees and shrubs make up the showiest groves, including European and Asian Lilacs, Asian Tree Peonies, Japanese Flowering Cherries, Crabapples, Flowering Pears and Mock Oranges.

Summer highlights

Colorful blooms continue in the display gardens, particularly daylilies, irises, hostas and drought-tolerant species.

Fall highlights

Experience vibrant fall colors with the Red and Sugar Maples, Oaks and Ashes in Eastern North America to the golden yellow Larches in Western North America and the Flowering Pears and Cherries in Asia.

Winter highlights

Even in winter, nature puts on a show with colorful fruits from crabapples, hawthorns, roses and Asian vines.