Stephen Albert
Plant sweet potato sprouts (called “slips”) in the garden 2 to 3 weeks after the last frost. Night temperatures must stay warmer than 60°F (16°C) and the soil temperature should be at least 65°F (18°C) for sweet potatoes to thrive.
Start purchased slips or sprout your own about 6 to 8 weeks before setting sprouts in the garden. Short-season gardeners can start earlier and protect plants from late frosts.
Sweet potatoes grow best in long-season regions (150 to 160 days of frost-free weather) where summers are hot but not excessively rainy. The optimal temperature range for best growth is 70°to 85°F (21°-29°C).
Sweet potatoes can take as many as 170 days to reach maturity, but some varieties can be harvested at about 100 days. Sweet potato tubers often double in size in the final month. Tubers of good quality can be harvested immature. Harvest mature tuber immediately after the first frost.
How to start slips
Young sweet potato plants are called slips. You can start slips by setting a whole sweet potato tuber in moist rooting medium. Keep the tubers warm. Sprouts will grow from the tuber and root. When they are 4 to 8 inches (10-20cm) tall, gently pull them from the mother tuber. You can grow them on in individual pots until it is warm enough to plant them in the garden.
Planting sweet potatoes in the garden
To plant sweet potato slips in the garden create a furrow 2 inches (5cm) deep and 12 inches (30cm) wide and fill it with aged compost or commercial planting mix. Ridge soil 10 inches (25cm) high over the furrow. Insert the slips into the soil 2 to 5 inches (5-12cm) deep spaced 15 inches (38cm) apart along the ridge.
Sweet potato planting dates
(These dates are for the Northern Hemisphere)
| Average date of the last frost | Planting dates |
| Jan. 30 | Feb. 15-May 15 |
| Feb. 8 | Mar. 1-May 15 |
| Feb. 18 | Mar. 20-June 1 |
| Feb. 28 | Apr. 1-June 1 |
| Mar. 10 | Apr. 10-June 1 |
| Mar. 20 | Apr. 20-June 1 |
| Mar. 30 | May 1-June 1 |
| Apr. 10 | May 10-June 10 |
| Apr. 20 | May 20-June 10 |
| Apr. 30 | Season is too short |
| May 10 | Season is too short |
| May 20 | Season is too short |
| May 30 | Season is too short |
| June 10 | Season is too short |
Sweet Potato planting details
- Planting depth: Set slips 4 to 8 inches deep
- Space between plants: 15 inches
- Days to harvest: 100 to 170
- Storage period: 4-6 months
- Suggested varieties: Allgood, Beauregard, Centennial, Jewel, Vardamen
Related sweet potato growing articles:
Sweet Potato Plant Starting Tips
