When to Divide Sweet Potatoes
Sweet potatoes grow year-round in USDA plant hardiness zones 9 to 11, but in cooler climates, sweet potato tubers must be stored in a cool, dry area for the winter. Either way, spring is the best time for splitting sweet potatoes. Divide in-ground sweet potatoes as soon as new shoots measure 1 to 2 inches (2.5-5 cm.). Divide winter-stored sweet potatoes as soon as you remove them from storage – after all danger of frost has passed.
How to Divide a Sweet Potato Vine
Carefully dig in-ground tubers from the ground with a garden fork or trowel. Rinse the freshly dug tubers gently with a garden hose to remove excess soil. (Winter-stored sweet potatoes should already be clean.) Discard any soft, discolored, or rotted tubers. If the damaged area is small, trim it off with a knife. Cut the tubers into smaller chunks. Be sure every chunk has at least one “eye,” as this is where new growth begins. Plant the tubers into the soil, about 1 inch deep (2.5 cm.). Allow about 3 feet (1 m.) between each tuber. Sweet potatoes benefit from full sunlight, but afternoon shade is helpful if you live in a climate with hot summers. You can also plant tubers in a pot filled with well-drained potting mix. Water the tubers as needed to keep the soil evenly moist but never soggy. Overly wet soil can rot the tubers.