Non-native trees and shrubs, often planted in home landscapes for ornamental purposes, can easily escape into natural areas where they grow quickly and compete with native plants for resources.
Many invasive woody plants are regulated by the Illinois Exotic Weed Act. The act makes it illegal for anyone to buy, sell, distribute, or plant any parts of the listed species without a permit. Woody plants included in this list are: multiflora rose, buckthorns (including glossy, saw-toothed, dahurian, Japanese, and Chinese), bush honeysuckles (including spring, Amur, Morrow’s and Tatarian), and olives (including Russian, thorny, and autumn).
After removing invasive species, existing native plants may need help recovering. In some cases, replanting with native plants may be necessary for restoration. When planting native species, try to use local-ecotypes of seeds or plants from within 100 miles of your location. Local ecotypes of native plants are adapted to local climates and can be easier to grow. They also provide food and shelter for pollinators and other wildlife. Restoring diverse native plant communities will help prevent future invasions by strengthening the ecosystem, but continue to monitor for invasive species.
Invasive shrubs, trees, and vines are a serious threat to native plants and natural areas in Illinois. Species such as Amur honeysuckle and common buckthorn can grow so dense that they nearly block all of the light to the forest floor. Vines, like Oriental bittersweet can wrap around trees so...
Presented by Ryan Pankau, Extension Educator, Horticulture Illinois forests are unique plant communities of towering trees as well as tiny, spring wildflowers. Invasive plants threaten native plant diversity in forest communities across Illinois by out-competing our natives for water, light, and...
We have included the most common and problematic plant species of Illinois environmental, agricultural, and horticultural concern on this website. It is not a comprehensive list.