Kudzu, Japanese stiltgrass and English ivy have invaded woods all over the Southeastern U.S., choking out native plants and reducing forest health and diversity. These plants are also really annoying for homeowners. I find myself sweating and cursing as I yank them out all spring, summer and fall. Controlling invasive plants can be a big job, and there are many days I’d rather avoid the mosquitoes and drink a glass of wine. Still, if you let them go, the job won’t get any easier. Fall is the best time to tackle these three invasives because they are about to release thousands of seeds into your yard that will produce plants for many years.
English Ivy
I’ll start with English ivy because it’s the one invasive plant on my list that is intentionally used for landscaping today. Sadly, this European native continues to be sold in many garden centers. English ivy smothers forest floors, weakens trees and can eventually kill them. A mature vine produces tasty berries for the birds along tree trunks and up in the canopy.
I have been strategically removing English ivy from one area of my garden at a time. If you find the prospect of tearing out hundreds of vines daunting, there is a simple and effective method for preventing English ivy from spreading far and wide. Remove any climbing vines from your property in the fall, especially those that bear fruit. Then look around for any berries visible at ground level. Mature English ivy has more rounded leaves lacking the usual lobes. If pulling mature vines seems too much to tackle, cut off all berries before they ripen. Also cut your climbing vines at the base of trees or structures. Perhaps you’ll have more time and energy to rip out those vines another day.
Japanese Stiltgrass
Japanese stiltgrass is an invasive annual grass accidentally introduced to the U.S. This multi-leaved grass grows to 3 feet tall where undisturbed in the garden. Stiltgrass commonly grows in thick patches along forest edges, shading out native plants. It survives mowing just fine and disguises itself in shadier parts of the lawn. This grass also will inconveniently weave itself through flowerbeds, making it tough to keep track of. Each plant produces up to 1,000 seeds in the fall that can survive for the next four or five years. That’s why it’s so important to remove this plant now.
Fortunately, Japanese stiltgrass is really easy to pull, especially if the ground is a little moist. You can recognize it by the faint silvery stripe on the midrib of its leaves. Sometimes you can control stiltgrass by mowing or weed whacking right before it is preparing to produce seed. The plants will die back each fall, so any grass that appears the following spring is a new generation.
Kudzu
Most anyone who lives in the South is familiar with kudzu, the East Asian vine that was intentionally and regrettably planted for erosion control until the 1950s. The three-leaved, hairy vines can grow a foot a day, swallowing entire stands of trees. Kudzu is also trying very hard to swallow a corner of my lot. The plants produce pretty purple flowers in summer that eventually become a grape-like cluster of berries.
Mature kudzu roots penetrate quite deep, making it difficult to remove larger plants. The best approach is to mow, cut or rip vines at the base several times a year. Definitely remove any berries before they ripen to a dark bluish-black color. Eventually the plant will weaken and never return.
As a plus, kudzu leaves are edible for both livestock and humans. Maybe it’s time to try out that kudzu quiche recipe.