Kudzu Plant Profile

Invasiveness and Special Considerations

Invasive kudzu vine covering the ground and trees in southern Alabama

Martha Snider / Getty Images 

Kudzu is a perennial invasive vine that was introduced in the United States from Asia in 1876. For a long time, it was viewed as a “wonder plant”—in the 1930’s the government paid landowners in the southeastern United States eight dollars per acre to plant kudzu for erosion control and cattle grazing.

But kudzu was the plant version of a Trojan horse of the worst kind. It is a highly invasive species that smothers other vegetation, including native plants. The vine can grow up to 100 feet long into the crown of the tallest trees, depriving them of light and choking them, or making them collapse from the sheer weight of the vine, which can reach ten inches in diameter. It engulfs even man-made structures such as power lines, road signs, and buildings.

It was estimated in 2001 that kudzu covers more than an estimated five million acres of forest land, which is more than five times the size of Rhode Island. Kudzu mainly occurs in the southeastern United State but has also been reported in northern states like Pennsylvania.

For homeowners, it is crucial to identify and control kudzu early because once it has taken hold, it is very difficult and lengthy to eradicate.

Kudzu leaves have three broad. lobed leaflets
Kudzu leaves have three broad. lobed leaflets. TravisPhotoWorks / Getty Images

Invasiveness of Kudzu

Kudzu spreads primarily through runners, rhizomes, and vines. It can also be dispersed through seeds.

An established kudzu plant grows quickly, up to one foot per day up to 100 feet long. It overgrows anything in its way, blocking the sunlight, and depriving plants of water and nutrients so they die. It girdles tree trunks, and breaks branches and whole trees because they cannot withstand the immense weight.

Kudzu develops a huge taproot of up to six feet long, which alone can weigh up to 400 pounds.

Gardening Considerations

To find out if kudzu has been detected in your county, contact your local Extension Office. In any event, it’s a good idea to familiarize yourself with its characteristics.

Botanical Name Pueraria montana var. lobata
Common Name Kudzu, East Asian arrowroot
Plant Type Perennial
Mature Size Up to 100 feet length
Bloom Time Summer
Flower Color Purple

Identification

Kudzu has alternate compound leaves with three broad leaflets up to four inches across. All of the leaflets are attached to the leaf stem. The central leaflet has three lobes, whereas the two outer leaflets have only one to two lobes.

The leaves have tiny hairs and feel fuzzy when you touch them. Note that the plant is not toxic, so it’s OK to touch it. As a member of the pea family (Fabaceae), kudzu is in fact edible, which should not tempt you to grow it, ever!

In the late summer, August or September in the southeastern United States, purple-reddish, spike-liked fragrant flowers appear on the vine. The smell of the flowers is sometimes likened to grapes.

After the bloom, they become flat, hairy seed pots about two inches long. They turn brown as they dry. Each seed pod contains three to ten seeds.

Kudzu has spike-like purple-reddish flowers in late summer
Kudzu has spike-like purple-reddish flowers in late summer. bungoume / Getty Images

Where Kudzu Is Found

Kudzu is mainly found in non-cultivated land such as abandoned fields, in ditches, and along roadsides. However, that does not mean it cannot pop up in your yard, especially in larger properties with open space or woodland.

How to Remove Kudzu

Unfortunately, there are neither quick nor easy ways to get rid of kudzu—unless you have goats or sheep, which love to eat kudzu. Most herbicides, including glyphosate as the active ingredient (Roundup), have only limited effect and only when the plants are fairly small. As kudzu is fire resistant, burning the roots can only weaken the plant but not eradicate it.

There are two different mechanical ways how you can tackle kudzu: above ground and below ground. Both require diligence and persistence.

Above ground, start by cutting the vines at the ground level, then follow up by regularly mowing or hand-cutting any emerging shoots until there is no more new growth. Kudzu is weakened over time by repeated regular defoliation. You might have to do this weekly during the growing season for as long as two years until it’s fully gone. Make sure to safely dispose of all the cut plant parts in the garbage.

Kudzu sends out new growth from the root crown but not the entire root below it. For this reason removing the root crown is crucial. Cut the root just below the root crown with a handsaw or, if the root crown is smaller, with pruning shears. If the root crown is still intact or any vines are left in the soil, kudzu will grow back.

It’s important to keep a close eye on the area for a couple of years before you declare victory. And, equally important, replant the area with a desirable landscaping plant to fill the space. Do not leave it bare because this increases the risk of kudzu reestablishing itself.