Organic Sweet Potato Growing Guide
Sweet Potatoes can be grown successfully in all 50 states. They do best with ample sun and heat and need at least 90 days frost free in most climates. The amount of heat units determine time to maturity, so if you live in a climate where the heat of summer means daytime temperatures 85 degrees or higher, you can grow sweet potatoes. We do recommend black plastic mulch for Northern growers.
Sweet potatoes are grown from 'slips', sprouts that are cut from the 'mother' sweet potato in a greenhouse production bed. Sweet Potato Slips will arrive wilted despite having been cut and gently wrapped in moist paper before being mailed promptly to your door. Slips will rarely have roots developed at this time. This is normal! Green stems will grow into lush vines. We recommend planting your slips right away for best results. If you can't plant immediately, unwrap the slips and spritz them with water to keep them moist. We do not recommend putting them in a glass of water.
Plant slips 10''-18'' apart in rows spaced 24''-36''. Slips can be placed in raised hills or beds. Place slips several inches deep in soil- this should cover several root nodules. Keep soil moist for the first several weeks after planting. Keep on top of weeds early, and eventually the vines of the plant will spread and out-compete most weeds. Sweet potatoes are beautiful plants that vine prolifically and sometimes show striking flowers similar to those of morning glory, to which they are related.
Water deeply and consistently throughout the season, tapering off a bit towards harvest time. Sweet potatoes should be harvested before or soon after the first frost in the Fall. Each plant should produce approximately 2-4 pounds of sweet potatoes that can be hand dug with a shovel or fork.
Cure harvested roots for 5 days in a hot and humid environment as close to 85 degrees and 95% humidity as you can provide. This can be done in a shaded area of a greenhouse or in a room with a humidifier. If these conditions are not available, layer roots in newspaper in closed boxes for several weeks. Cured roots can be stored for 6-10 months at 55-65 degrees.