Note: Out of concern for the health of our community during the COVID-19 pandemic, the Visitor Center will be closed and Arboretum events are cancelled until further notice. COVID-19 updates»

The Arboretum offers free informational tours in Longenecker Horticultural Gardens (LHG) and the Wisconsin Native Plant Garden (WNPG). Tours take place on selected dates from April through October, Wednesday evenings from 7 p.m. to dusk, or Saturday afternoons from 1 to 3 p.m. Tours are open to the public and begin at the Arboretum Visitor Center. They are intended for adults.

With more than 2,500 types of plants on display, Longenecker Horticultural Gardens feature an internationally recognized collection of trees, shrubs, and vines. It is a resource for the study of landscape plants by educators, the public, and the nursery trade. The gardens hold major displays of lilacs, flowering crabapples, viburnums, conifers, and many other plant groups.

The 4-acre Wisconsin Native Plant Garden surrounds the Visitor Center with several hundred species native to Wisconsin. The garden serves as an introduction to ecological restoration and the restored and managed plant communities in the Arboretum. It also demonstrates how to incorporate native plants into home landscapes.

Tours are led by Arboretum garden staff—including Susan Carpenter, the WNPG gardener, and David Stevens, the LHG curator—and other regional experts. Tours are cancelled for severe weather.

2020 Garden Tours

Saturday, April 25, 1–3 p.m. Magnolias – CANCELLED

Tour Longenecker Horticultural Gardens’ extensive magnolia collection, and other spring flowering plants encountered along the way, with Michael Jesiolowski, Janesville Rotary Botanical Gardens’ director of horticulture.

Saturday, May 2, 1–3 p.m. Early Signs of Spring – CANCELLED

As trees begin to leaf out, Dutchman’s breeches, twin-leaf, and rue-anemones might be blooming in the Wisconsin Native Plant Garden woodland gardens, and prairie-smoke in the prairie gardens. Susan Carpenter will lead this tour.

Saturday, May 9, 1–3 p.m. Lilacs – CANCELLED

Established in 1935, the Longenecker Horticultural Gardens lilac collection is one of the largest in the country. Join Zane Fuller, Arboretum horticultural technician, to explore lilac history, lore, culture, and color.

Saturday, May 16, 1–3 p.m. Crabapples – CANCELLED

With over 200 trees, the Longenecker Horticultural Gardens collection is the most up to date in the country. Learn why crabapples are the most planted flowering tree in the Midwest with David Stevens, Gardens curator, as he highlights some of his favorite selections.

Wednesday, June 17, 7 p.m. Woodland, Savanna, and Prairie Gardens – CANCELLED

Celebrate late spring by visiting our woodland, savanna and prairie gardens. This tour, led by native plant gardener Susan Carpenter, provides an overview of the Wisconsin Native Plant Garden.

Saturday, June 27, 1–3 p.m. What’s in Bloom? – CANCELLED

Join Susan Carpenter to find, compare, and learn about flowers on native trees, shrubs, and herbaceous plants in the Wisconsin Native Plant Garden.

Sunday, June 28, 1–3 p.m. Milkweed and Monarchs – CANCELLED

Visit the Wisconsin Native Plant Garden to identify milkweeds and nectar plants that support monarch caterpillars and butterflies, and learn how to grow them in your garden. Susan Carpenter, native plant gardener, will lead this tour.

Wednesday, July 15, 7 p.m. Plants for Pollinators – CANCELLED

Learn more about summer-blooming native and ornamental species in Arboretum gardens. Susan Carpenter, native plant gardener, will highlight plants and gardening practices that support essential pollinators in urban/suburban landscapes.

Wednesday, August 5, 7 p.m. Native Grasses – CANCELLED

Susan Carpenter, native plant gardener, will focus on color, size, and features of native Wisconsin grasses, from tiny mustache grass to big bluestem on this tour of the Wisconsin Native Plant Garden.

Saturday, September 19, 1–3 p.m. Fall in the Native Plant Garden

Color, fruits, seeds, late blooming plants, late-season insects—we will find these and more in the diverse Wisconsin Native Plant Garden around the Visitor Center. Susan Carpenter, native plant gardener, will lead this tour.

Saturday, October 10, 1–3 p.m. Conifers

Zane Fuller, Arboretum horticultural technician, will explore the Longenecker Horticultural Gardens pinetum, the largest and most diverse conifer collection in the state. Located on a glacial drumlin, the collection presents conifers from around the world.

Saturday, October 17, 1–3 p.m. Fall Favorites

Enjoy the colorful show of Longenecker Horticultural Gardens trees and shrubs before winter dormancy. Michael Jesiolowski, Janesville Rotary Botanical Gardens’ director of horticulture, will highlight the best fall foliage, form, and fruit displays from Acer to Zelkova.