The vine known as Kudzu (Pueraria montana var. lobata) gained its reputation as “the vine that ate the South” due to its aggressive, rapid growth. This highly invasive species can blanket entire fields and forests, leading many to assume that the harsh cold of winter must finally kill it. While its massive green canopy disappears in late autumn, the plant is not dead; it is merely employing a survival strategy that protects it from the cold.
Kudzu’s Seasonal Dormancy
When the first hard frost arrives, the extensive, above-ground growth of Kudzu begins to wither and collapse. This process, where the leaves and vines turn brown and decay, is the visible sign of the plant entering seasonal dormancy. The entire living mass seems to vanish, leading to the mistaken belief that the cold has killed the plant.
This die-back is a necessary adaptation for the perennial vine to survive the colder months. Kudzu is deciduous, shedding its foliage to prevent water loss and damage from freezing temperatures. The dead, matted vines and stems remain, but the active, photosynthetic parts of the plant are gone, setting the stage for its dramatic return in the spring.
The Overwintering Structure: Root Crowns and Tubers
Kudzu’s survival relies on its massive, underground root system, which remains insulated beneath the soil. This system is composed of the perennial root crown—the woody junction where the vine meets the root—and a network of thick, fleshy, tuberous roots. The root crown is the heart of the plant, containing buds that will sprout new vines once the weather warms.
The large, starchy tubers function as the plant’s storage reservoir, protecting it from freezing and fueling its renewal. These tubers can reach impressive sizes, sometimes growing up to seven inches in diameter and extending to depths between three and twelve feet below the surface. This substantial underground mass is packed with carbohydrates, which are energy reserves translocated from the leaves before the fall die-off. These stored resources ensure the plant’s survival through winter and provide the energy for the explosive growth that allows Kudzu to quickly re-establish its canopy in the spring.
Targeting Kudzu During the Cold Season
The dormant period, when above-ground foliage is absent, offers a strategic window for control efforts. Since the plant’s energy is concentrated in the root crowns and tubers, winter provides an opportunity to target the perennial structure directly. The lack of leaves makes the woody crowns and main stems more visible and accessible near the soil line.
Physical removal of the crown is one method, made easier when the thick blanket of summer growth is gone. Certain systemic herbicides can also be applied using a cut-stump method, where the chemical is painted directly onto the freshly cut crown. This technique is effective because the herbicide is concentrated onto the living tissue connected to the main energy reserve. The ability to use this targeted approach, even at temperatures as low as 40°F, makes the cold season a valuable time for management.