How Kudzu Works

How Kudzu Grows

Kudzu flower in bloom.
Kudzu flower in bloom.

Kudzu belongs to the legume family and is related to the pea, soybean, peanut, alfalfa, aster and oat. Interestingly enough, it's also related to the cannabis plant [source: Britton]. A legume is a plant that produces its fruit in the form of a pod. A kudzu's pod blossoms into a tall, purple flower that has a grapelike fragrance. In late summer, the flower turns into brown, flat, hairy-looking pods that contain anywhere from two to 10 seeds. The catch is that only kudzu vines draped over other plants or objects can produce seed pods, because blossoms grow from those hanging vines. An entire cluster produces two or three healthy seeds, but they can germinate even after several years of dormancy [source: Everest].

As any landowner who's dealt with kudzu can tell you, however, this lack of viable seeds doesn't make much difference in the kudzu survival rate. The secret to the plant's durability is in the roots -- they sprout new ones to reproduce very quickly. These root crowns are relentless and have been known to hitchhike in truckloads of fill dirt and take up residency hundreds of miles away. They set up camp right on the soil surface of the ground. From there, these starch roots grow as deep as 12 feet (3.66 meters) and can weigh up to 300 pounds (136 kilograms) [source: Everest]. These roots are rich in carbohydrates and have the unique ability to tap water from deep underground sources, which makes kudzu survive in dry, hot conditions where other plants can't.

At the ground's surface, kudzu vines sprout outward and upward from root crowns. New root crowns sprout every few feet along a vine, attach to the soil and spring yet more root crowns. Meanwhile, vines continue to grow as much as 2 feet (61 centimeters) a day in summer months. Attaching to a tree, pole, fence or building, kudzu can grow up to 80 feet (24 meters) high. That's why some people call it the "mile-a-minute vine."

Kudzu leaves grow in bunches of three and measure 2 to 4 inches (5 to 10 centimeters) in diameter. These leaves twist and turn, depending on the intensity of sunlight that's beaming down, to provide optimal shade for their vines and roots while working their own version of photosynthesis. Photosynthesis is how green plants turn sunlight and water into the energy they use for food.