It is deciduous, losing its leaves in the fall following a killing frost. Fragrant purple flowers form in late June to early July on vines draped three feet or higher into trees, fences and other objects. Flowers are rarely produced in open patches on flat ground. The hard-coated seeds can remain viable for several years before they germinate. Burning scarifies the hard seed coat permitting germination.
Vines grow from buds on a root crown at the soil surface.
As the vines spread, rooting occurs from buds at each node on a vine. With vine growth of up to 50 feet in a single growing season, a single plant can spread to cover large areas each year. Roots developing from the vine nodes usually enlarge into root crowns from which additional vines will arise. Mature stands of kudzu may have root crowns every 1 to 2 square feet. Roots of the established crowns can reach several inches in diameter and may grow to depths of three feet.