In case you haven’t heard; Butterfly Bush, Summer Lilac; Buddleia davidii is now considered an Invasive Species in Oregon. Just like Purple Loosestrife, Lythrum salicaria, a popular water garden plant; butterfly plants have escaped into the wild and are crowding out our native plants in the wild.
I am beyond overjoyed that English Ivy, Hedera helix, is also on the Invasive Species list and as soon as stocks are sold out will no longer be available. One look at Deepwood Park in Salem or Forest Park in Portland is enough to sour you on how it can take over and crowd out native plants our native animals depend on to live. (I am saddened because I love Ivy as an indoor plant.)
What the new classification means to home gardener is this: These plants are no longer for sale in Oregon and they may not be shipped or brought into the state. Gardeners are also requested not to share plants, cuttings, or seeds.
Back 15 years ago, when I was going to school, we discussed the use of a great many plants. I think all my professors were saying that some plants were so aggressive that their use in the garden should be banned and most of us students agreed. It makes no sense to use plants that escape and endanger our native flora and fauna.
Having said that, I absolutely love my Buddies. I have one that was a present from my mom and another that was bred just for me. This wonderful grad student bred a bunch of Buddleias and named them for a group of us ‘older’ women getting their degrees. Since I love yellow, he named his best yellow for me and gave me a start. I love my ‘Suzie’ plant to bits.
Buddleias can produce thousands and thousands of seeds; or just a very few. If you find seedlings around your yard, you have one of the aggressive varieties. Just dig and throw the seedlings into the garbage. Be sure to keep your plants deadheaded (removing flower heads before they go to seed.) Pick up the clippings when you trim the plant. Either burn them or send to your local composting service if you cannot put them in the garbage. DO NOT dump your clippings. Buddleias regenerate from clippings and that is the most common way of releasing the plant into the wild.
There are plenty of other garden plants that have escaped to the wild. Some from tasty fruit that the birds eat and poop out the seeds along with a fresh fertilizer packet; English Holly, Ilex aquifolium; European Hawthorne, Crataegus monogyna; Himalayan & Armenian Blackberry, Rubus armeniacus, R. discolor, R. procerus By wind sown seeds; Bachelor’s Button (I thought it was a native), Centaurea cyanus; Fennel, Foeniculum vulgare; Salt Cedar, Tamarix ramosissima; Tree of Heaven (A Tree Grows in Brooklyn (P.S.) one of my all-time favorite books), Ailanthus altissimo. Tomato seedlings are found where ever sewage sludge is spread.
It is up to us gardeners to keep up on what is escaping from our gardens and go the extra mile to keep that from happening. To that end I would like to recommend some books and websites where you can get more information about being a thoughtful gardener.
I read Noah's Garden: Restoring the Ecology of Our Own Backyards when it first came out 15 years ago. It is still relevant today. The second book is Planting Noah's Garden: Further Adventures in Backyard Ecology as good as the first.
I would direct you to your Land-grant College or University and your state Department of Agriculture for more information on Noxious and Invasive Plants and Weeds. The USDA Plants website is a plant nerds heaven with links for Invasive and Noxious Plants as well as links for Natives, Endangered, and Recommended Plants for your area. Here in Oregon, you can go to the following sites: ODA Plant Division Noxious Weeds, OPB Silent Invasion Special, Garden Smart flyer, or Oregon State Extension.