07/20/2025
Japanese lilac trees are now being recognized as invasive in New England and areas of upstate NY. Unfortunately, some garden centers are still selling them and some local landscapers are still planting them.
"Do not plant Japanese tree lilac." ~Adirondack Park Invasive Plant Program
There is a lot of talk and some action regarding currently listed invasive plant species, but few consider what our FUTURE invasive species will be. This tree could be one of them: the Japanese tree Lilac (Syringa reticulata).
They are blooming right now in the state and are easy to pick out. Look for their spray of flowers, and you'll start to see them planted by the thousands along streets, subdivisions, and shopping malls. The species has won several nursery trade/landscaping awards and seems to be one of the "it trees" for Urban Foresters. Webpages touting the tree list its wildlife benefits as "good for insect pollinators and hummingbirds." This tree is native to Asia, specifically Japan, northern China, Korea, and parts of Russia. The Arnold Arboretum of Boston introduced it as a landscape tree in 1876. Its escape from cultivation as a naturalized species is most documented in the New England area.
You'll become more alarmed if you dig beyond the nursery trade on this species. The Adirondack Park Invasive Plant Program (APIPP) webpage for this species says, "Japanese tree lilac can escape cultivation and dominate natural areas, excluding native trees and shading out native plants in the understory. Do not plant Japanese tree lilac." The University of Pittsburgh has found it is popping up all over campus and along the riparian corridor nearby and are conducting studies on it. The Invasive Plant Atlas has confirmed escape of this species in Minnesota, Wisconsin, and even Indiana, specifically at Holliday Park by Kevin Tungesvick.
We remained shocked that we've not learned the lessons that Callery pear, autumn olive, and many other non-native (turned-invasive species) should have taught us. Urban foresters, arborists, and city planners plant these (sometimes with our tax dollars) with seemingly no regard (or research) for the ecological threats these plants could have in the future. Furthermore, they have the audacity to sell people on their "wildlife benefits."
Take a moment and notice how many of these trees are in your community. Not only does every tree produce a massive seed bank that has the potential to threaten our biodiversity and ecological sustainability for years to come, but it also replaces a native tree that should be contributing to our local ecosystem and adding to our community's natural heritage. We must demand better from those who have power over these critical ecosystems.
