The sweet potato vine (Ipomoea batatas) is a vigorous plant often cultivated for its striking ornamental foliage. This perennial, a member of the morning glory family, is commonly grown as an annual in cooler climates due to its sensitivity to frost. Propagating the vine from a tuber is a straightforward and economical way to create new plants for containers or garden beds. The process encourages the tuber to produce small sprouts, known as “slips,” which are then removed and rooted to establish a new vine.
Selecting the Best Starting Material
The initial step involves choosing a healthy sweet potato tuber to act as the source material for the new vines. While any grocery store sweet potato can potentially sprout, selecting a certified organic tuber is recommended. Conventional sweet potatoes are sometimes treated with a sprout inhibitor, which can prevent or delay the growth of slips. A healthy tuber should be firm, free of soft spots, mold, or decay. The presence of small, hair-like roots or tiny bumps, which are latent buds, indicates a good candidate for sprouting. Alternatively, you can acquire ready-made slips or vine cuttings from a garden center or online supplier.
Generating Slips Using Water Propagation
The most common method for encouraging a tuber to produce slips is suspension in water, which activates the latent buds. Insert three or four wooden toothpicks evenly around the middle of the sweet potato to create a stable support structure. Fill a glass jar with water and suspend the tuber so the bottom half, or the narrower, pointed end, is submerged. The wider, blunt end should remain exposed to the air.
Place the jar in a warm location that receives bright, indirect sunlight, as heat and light initiate growth. Change the water every three to five days to prevent mold and ensure the potato has access to fresh oxygen. Within a few weeks, slips will begin to emerge from the submerged portion of the tuber. The slips are ready to be twisted or cut from the parent tuber when they reach four to six inches long and have developed small, white adventitious roots at their base.
Planting Your New Vines and Initial Establishment
Once the slips have been removed from the tuber, they are ready to be planted in a permanent growing medium, either in containers or directly into the garden.
Hardening Off Slips
If your slips were started indoors, they must undergo a process called “hardening off” to acclimate them to outdoor conditions. This involves gradually introducing the young plants to direct sun and wind over a period of about seven to ten days, starting with just a few hours a day.
Planting Medium and Technique
Sweet potato vines thrive in a well-draining, loose soil that is rich in organic matter. If planting in a garden bed, amending heavy clay soil with compost or sand will improve drainage and aeration, which is necessary for root expansion. Plant each slip deep enough so that at least two nodes—the points where the leaves were attached—are buried beneath the soil surface, with only the top leaves remaining above ground.
Initial Watering
After planting, water the slips immediately and thoroughly to settle the soil around the developing roots. The soil should be kept consistently moist for the first one to two weeks, which reduces transplant shock and encourages the new vines to establish a robust root system.