As a part of our work for landowners, WCSW staff and volunteers spend time helping them find invasive plants on their land and plan for controlling them. Late fall is our favorite time to survey for invasives in fact, because at the end of October and early in November, many invasive plants stand out like a sore thumb. When most of our native woody plants have shed their leaves, several of our most troublesome invasives still have theirs and so are easily seen. In fact, the longer period many of these plants keep their leaves gives them a growth advantage over our native plants. Take a look at these photos. In each, the invasive plants have yellow leaves while natives are bare. Asiatic (or oriental) bittersweet, a vine, can be seen climbing trees as towers of yellow leaves, and with the characteristic orange and red berries used for fall decorations in the past. Instead of using bittersweet berries, you can decorate with the bright orange and red berries of winterberry holly, a native shrub that lives near wet areas. Keep in mind, it is now illegal to sell decorations with Asiastic bittersweet berries on them.
A common invader of forest understories in Midcoast Maine is the exotic shrub honeysuckle, of which there are several species, all equally destructive. They can grow so prolifically that trees cannot regenerate under them. If you look around now and see a forest understory of shrubs with yellow leaves, it may be exotic honeysuckle, or perhaps glossy buckthorn, a small tree that also keeps its leaves into the late fall. As far as larger trees go, our native oaks are still sporting some red to brown leaves now, but most other native trees are bare, so the bright yellow and orange leaves of the invasive Norway maple really stand out. Japanese knotweed keeps its leaves into the late fall as well, and its bare reddish stems can be seen standing all winter.
After you’ve checked around for invasives, you can call us for management advice. We can visit your property and write up recommendations for how to rid your land of these plants which reduce natural diversity, timber regeneration and wildlife habitat quality. If you are eligible for NRCS EQIP programs, you also qualify for free invasive plant management plans.