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Last week I talked about the Georgia Forestry Commission’s dirty dozen and gave a brief overview of each one. This week I’m going to go more in depth and talk about some ways to identify and control some of these that are problematic in the mountains. I’ll cover Nepalese browntop (Japanese stiltgrass), privet, kudzu, and autumn olive.

Let’s start with the Japanese stiltgrass. This is on the only annual that I chose, so its control will be a bit different. Japanese stiltgrass looks like a miniature bamboo. It has alternate leaves. It can grow up to 2 feet tall. It likes to grow in shaded areas, so it can grow in shaded lawns and in forests. Japanese stiltgrass will put on seedheads during the fall. The seeds are small, light colored, and sticky. Controlling it can be very challenging. In lawns, herbicides or hand pulling can be done. A pre-emergent herbicide that is also effective against crabgrass will prevent it from germinating. A product with the active ingredient prodiamine will work. Japanese stiltgrass germinates earlier than crabgrass so the application would need to be done in early march. In forested areas there are no herbicides labelled for use. That means that you will have to either hand pull or cut it back in the fall before it goes to seed. Most likely, there is already seed stored in the soil; therefore, you will need to cut it back several years in a row to deplete the soil seed bank.

Chinese privet can be identified at this time of year because it has BB sized fruits hanging on it. Chinese privet starts out as a bush that can grow to be over 20 feet tall, if left unchecked. The leaves on it are glossy, oval shaped, and a little bigger than a quarter.

Most people know what kudzu looks like. It is a vine that is capable of covering entire trees. Kudzu leaves are trifoliate which means they come in threes. They also have purple flowers, but can be hard to find because they’re hidden behind the leaves. As members of the legume family they have hairy pods.

Autumn olive is a bush that that can get up to about 15 feet high. Their leaves are a silvery white color on the bottom. They put on a red fruit that has gray specks on it. The fruit is edible and is spread by birds and other wildlife.

Tactics for controlling perennial plants are different from annuals. Cutting them back is an option, but these plants will keep growing back from their roots. It would take several years of cutting back regrowth to eliminate invasive perennials. Hand pulling can be done while the plants are still small, but you need to remove the entire root system.

Herbicides are usually the most effective way of controlling perennial invasive plants. Even with herbicides, it will take a couple of seasons to get full control. For perennials, you should apply herbicides in the fall. During the fall perennials are moving as many carbohydrates and energy down into their roots as possible. Therefore, if you apply a systemic herbicide the plant will also move the herbicide down into the roots, making the herbicide more effective. As always, whenever you use an herbicide read and follow the label.

If you have questions about identifying or controlling invasive weeds contact your county Extension Office or email me at Jacob.Williams@uga.edu.

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