The sweet potato vine (Ipomoea batatas) is cultivated globally for its edible, starchy tubers and decorative foliage. This vigorous, trailing plant is often used in garden beds, containers, and hanging baskets during the summer growing season. Because it produces energy-storing root structures, many gardeners wonder if this plant will return on its own the following year. Whether the plant regrows depends entirely on the climate and the specific steps taken to protect the underground storage roots.
Tropical Roots and Hardiness Zones
The simple answer to whether the sweet potato vine comes back depends on where you live. The sweet potato is a tropical species and a true perennial, meaning it naturally lives for more than two years. Its perennial nature is only expressed in warm regions, specifically USDA Hardiness Zones 9 through 11, where the ground never freezes solid.
In these warm climates, the above-ground foliage may die back during a cool spell, but the underground roots remain healthy and sprout new vines when temperatures rise. In most temperate zones, however, the plant is treated as an annual. An annual completes its entire life cycle within a single growing season.
Gardeners outside of tropical zones must replant their sweet potato vines each spring because winter weather is too severe for the plant to survive unprotected. The dividing line between perennial and annual cultivation is determined by the plant’s sensitivity to cold. The survival of the plant relies completely on the health of its subterranean storage roots.
Why Cold Temperatures Stop Regrowth
The inability of the sweet potato vine to return naturally in cooler climates is due to the vulnerability of its storage roots to low temperatures. While the leafy vines above ground die quickly after the first light frost, this event does not immediately kill the entire plant. True regrowth failure is caused by sustained cold reaching the roots beneath the soil surface.
The storage roots are highly susceptible to chilling injury, which begins when soil temperatures drop below 55°F (13°C). Exposure to these cool temperatures, even above freezing, can damage the root’s internal structure, potentially leading to internal decay. Final destruction occurs when the soil temperature drops to 32°F (0°C) or below, causing the water within the root cells to freeze.
Freezing water expands, rupturing the cell walls of the storage root and destroying the plant’s ability to sprout new growth in the spring. Therefore, for the plant to survive and regrow, the storage roots must be removed from the ground before the soil becomes too cold. This intervention is the only way to bypass the climate barrier and ensure the vine’s return the following year.
Storage Methods for Next Season
To successfully bring your sweet potato vine back next season, you must harvest and store the storage roots indoors before the first hard frost. The process begins by carefully digging up the roots, taking care not to nick or bruise the skin. Damaged roots should be set aside for immediate use, as they will not store well and may rot, potentially spreading disease.
After harvesting, the roots must undergo curing, which is necessary for long-term viability and flavor development. Curing involves holding the roots in a warm, humid environment for several days. Optimal conditions are a temperature range of 80–86°F (26–30°C) and a high relative humidity of 80–97% for 4 to 14 days. This warmth and humidity help the skin heal minor abrasions, preventing the entry of pathogens and minimizing water loss during storage.
Once cured, the roots are ready for overwintering, which requires different conditions. Long-term storage is best achieved in a cool, dark, and moderately dry location. Temperatures should be consistently maintained between 55–60°F (12–16°C). Basements, root cellars, or cool closets are often suitable spaces, provided they do not freeze.
The cured roots should be packed in a breathable material and stored in a cardboard box or slatted crate to allow for air circulation. Suitable materials include newspaper, peat moss, or vermiculite. Check the stored roots periodically throughout the winter, removing any that show signs of shriveling, mold, or rot to prevent the spread of decay.