Kudzu

About

A fast, climbing pea-family vine from Asia that can grow up to a foot a day and blanket trees, sheds and fences. It spreads from rooting runners and woody root crowns, and big patches take years to clear.

Also called kudzu vine

How to identify it

Look for

Leaves are compound with three broad leaflets up to 4 inches across, sometimes lobed in sun, and drop at the first frost. Older vines turn woody with rough brown bark, and pea-like flowers grow in 4- to 8-inch clusters on climbing vines in mid to late summer, followed by pods about 1.5 to 2 inches long. Where a vine touches the ground it roots and forms a knobby root crown at or just below the soil surface.

Where it grows

Forest edges, old fields, roadsides and neglected yard corners, especially on deep, well-drained soils where winters are mild.

When

New growth starts in spring, flowers appear from about July to September, pods ripen in fall, and the leaves die back at the first frost.

How it spreads

Mostly by runners that root every few feet and form new root crowns; seed set is poor in North America, with only 1 or 2 good seeds in a cluster of pods.

Most common in

Where it is regulated

Kansas, Pennsylvania, Florida, West Virginia and Oregon list it as a noxious weed.

What to do, gentlest first

Start at the top. Weed killers are a last step; always read and follow the label.

1. Catch it while it's small Prevent

   Young patches with few root crowns are far easier to kill than old ones. Don't let vines climb trees or spread into your yard from a neighbor's lot; talk with neighbors about treating a shared line together.

2. Cut out the root crowns By hand

   Dig down with a shovel or pick to expose each root crown, cut just below it with a hatchet or saw, and remove it. You don't need to dig out the huge storage root, which can't sprout on its own.

   Bag or otherwise destroy removed crowns and vines; don't compost them.

3. Cut every vine to the ground, weekly By hand

   Cutting all vines to ground level about once a week (every 2 weeks at minimum) starves the roots. It can take several years, and trimming vines back now and then won't work.

4. Heavy grazing Natural enemies

   Steady, intense grazing by livestock can wear down younger kudzu patches by draining root reserves.

5. Glyphosate or triclopyr, twice a season Conventional spray

   Spray fully expanded leaves in late spring or early summer, then treat new growth again in late summer or fall. Cut-stump treatment works well when root crowns are exposed after mowing. Expect repeat treatments for several years.

   Read and follow the label. Many lawn and brush killers also harm garden plants, so keep spray and drift off anything you want to keep. Don't spray vines draped over trees, shrubs or gardens you want to keep; pull those vines down by hand instead.

Uses, wildlife and pets

For wildlife

Livestock graze it, and bobwhite quail eat the seeds in some areas.

Pets

Not listed as toxic by the ASPCA