How to Grow Japanese Sweet Potatoes and Potato Vines

Japanese sweet potatoes are grown from slips--sprouts taken from the original or parent tuber. Sweet potato slips may be purchased from nurseries, seed stores and garden supply houses, but are easy to propagate at home from store-bought tubers. After rooting, plant the slips in the prepared garden bed. A rich soil is not required, since they thrive in poor soil that would not support other vegetables. However, potato production is best obtained from a well-drained sandy soil.

Things You'll Need

• Rooting medium
• Sweet potato slips
• Water
• Mulch

Instructions

How to Grow Japanese Sweet Potatoes and Potato Vines

1. Bury tuber halfway in a pan or box of rooting medium--moist sand, sawdust or chopped leaves--six to eight weeks before you intend to plant them outdoors. Or you may suspend a tuber pierced with toothpicks about halfway into a water-filled jar. Either method will produce shoots in about four weeks. Allow two more weeks for shoots to mature to vines for planting.

2. Dig the planting bed soil to a depth of 8 to 12 inches to allow for long roots. Make ridges in the soil about 3 feet apart to allow good tuber development. A row of 10 feet will produce from four to eight pounds of potatoes. Potassium-heavy fertilizer may be used to aid in the growth of the potato tubers. Use nitrogen-based fertilizers only sparingly, as nitrogen will produce more vine growth and fewer potatoes.

3. Cut the shoots at an angle from the parent potato with a sharp knife, when they are 6 to 9 inches long, and remove the bottom inch from each slip to prevent any disease organisms. Plant the slips in a prepared garden bed in full sun after threat of frost has passed.

4. Bury the potato slips up to the last leaves about 6 inches deep and 12 inches apart in the soil ridges. Gently tamp down the soil and water thoroughly. Mulching with hay or grass clippings will eliminate the need for weeding and help to retain warmth and moisture.

5. Lift the potato vines occasionally to discourage rooting at the joints of the vine. If rainfall is not sufficient, provide an inch of water a week. Japanese sweet potatoes may be harvested four to six months from planting.

Tips & Warnings

• Japanese sweet potatoes easily survive drought, but will quickly rot with overwatering.

References

• Identifying Boniato-type Sweetpotato Cultivars Adapted to NC Growing Conditions
• "Slipping" Sweet Potatoes