Sweet potatoes grow from slips, which are shoots or cuttings taken from mature sweet potato tubers. Here is how the process works:
- Starting slips: Unlike regular potatoes grown from tubers, sweet potatoes are started from slips or plug plants. These slips can be grown by placing sweet potato tubers in warm, moist conditions (like moist sand in a propagator or airing cupboard) to encourage sprouting in spring. Once the leafy shoots reach about 2–3 inches (5–7.5 cm), they are cut off and rooted in pots or water until they develop roots
- Planting slips: Once rooted, the slips are hardened off (gradually acclimated to outdoor conditions) and then planted in warm soil, ideally when soil temperatures are above 65°F (18°C) and all risk of frost has passed. They are planted about 12 to 18 inches apart on ridges or mounds to improve drainage and soil warmth. The soil should be loose, sandy, and well-draining to allow tubers to grow smoothly
- Growing conditions: Sweet potatoes need full sun (at least 6-8 hours daily), warm temperatures, and consistent moisture, especially early on. Water well after planting slips until roots establish. Fertilize moderately, avoiding excess nitrogen which favors leafy growth over tuber development. Mulching or using black plastic can help warm the soil and suppress weeds
- Development: The plants produce long, leafy vines that spread. Each root can produce tubers underground. The tubers grow over the summer, maturing in about 85 to 120 days depending on conditions. As the plants vine, they shade out weeds, making weed control easier
- Harvest: Sweet potatoes are harvested after the foliage starts to yellow or before the first frost. The tubers are dug up carefully to avoid damage.
In summary, sweet potatoes grow from slips rooted from tubers, planted in warm, loose soil with good sun and moisture, producing vines above ground and edible tubers below ground over a warm growing season
