Invasive plants are those that have a tendency to take over an area if left unchecked. While we do have some invasive native plants in Kentucky the ones that cause the most trouble in our woodlands are invasive exotic plants. These invaders are not controlled by the insects, animals, or diseases that keep them in check in their homeland. If not addressed quickly, they can spread and become a serious problem for woodlands.
There are a wide variety of methods that can be used to address invasive exotic plants depending on the types of plants, their size, and densities. It is critical to match the control method appropriately to the plant and even then it is necessary to follow-up to ensure there is not a new invasion in the future.
Tree of Heaven
Tree-of-heaven (Alianthus altissima) is a fast-growing tree from Asia that has spread throughout the United States.
It produces abundant wind-blown seed that can readily germinate and grow rapidly into a large tree. It can establish in the understory of mature forests easily. In the open, it can outgrow many native tree species.
If you’re a woodland owner and have on or adjacent to your property a tree-of-heaven that is three or more inches in diameter, you will probably find it establishing along roads, trails, and any disturbance in your woodlands such as fallen trees or harvested woodland.
The most effective way to control tree of heaven is to pull seedlings by hand before the taproot develops. If the plant has matured, cutting alone will only help temporarily by reducing its ability to spread.
Chinese Privet
Privet in Kentucky refers to two species Ligustrum sinense, the Chinese privet, and L. vulgare, the European privet.
Introduced from China and Europe in the mid-1800s, both of these species were widely planted as ornamentals and for hedgerows and have now been reported as aggressive invaders of our woodlands.
Privet is a very serious pest plant south of Kentucky, with Georgia as its stronghold.
Controlling Chinese Privet in Kentucky can be accomplished mechanically with mowing, cutting and pulling as well as chemically with a thorough application of a number of commercially available herbicides