I’ve started gardening and have encountered a daunting problem: kudzu. I’ve tried Roundup, gasoline, digging, and cutting, but it always stays ahead of me.
Barbara Celtnieks, Wheaton, MD
Walter Skroch, emeritus professor of horticulture and specialist in weed science at North Carolina State University in Raleigh, replies: Kudzu is a tenacious plant commonly called “foot-a-day vine.” The best way to control this fast grower is with a pet goat. High in protein, kudzu is great animal feed.
If you’re not up to caring for a goat, the next best way is to contain kudzu’s root growth. This can be done by mowing the kudzu every two to three weeks or by cutting the vine back to the ground whenever it reaches 12 to 18 inches. At first, the kudzu will sprout back quickly. But in time, this will weaken the root system and the plant will die back. Allow up to two years to eliminate kudzu this way.
Like other legumes, kudzu is fairly tolerant to Roundup, but a stronger than recommended solution applied directly to dry leaves can be effective. Using Roundup, which comes as an 18 percent solution, mix 1 part solution with 9 parts water and lightly mist or paint it on the dry leaves. Avoid applying it on a rainy day, because the Roundup needs a minimum of six hours of drying time to be effective. The ideal time for applying Roundup is mid- to late summer, approximately two weeks after the kudzu has bloomed. Apply a second application in four to six weeks, and then again the following summer.