By Julie Christensen
If you’re looking for a vigorous, fast-growing vine for trailing in pots or in beds, sweet potato vine (Ipomoea batatas) just might be the ticket. Sweet potato vines are tropical plants that thrive in rich, moist soil. They tolerate a variety of soil Ph levels and grow in both full sun and partial shade. Best of all, sweet potato vines produce large, exotic leaves that come in a variety of colors, from neon green to black to pink or purple.
Sweet potato vines are tropical plants that are evergreen in USDA Plant Hardiness Zones 8 through 11, depending on variety. In cold climates, they shrivel up and turn mushy at the first hint of frost. Most northern gardeners grow them as annuals, although overwintering plants indoors is also an option for the ambitious gardener.
Propagating Sweet Potato Vine
To grow sweet potato vines, you have several options. The simplest, of course, is to buy nursery plants in the spring and plant them outdoors after the last frost.
You can also plant sweet potato vine from seed. Fill a seed-starting tray with a light, soil-less starting mix. Sprinkle the seeds over the tray, spacing them 3 inches apart and cover them with a light dusting of starting mix. Spray the mix with water from a spray bottle and cover the tray with plastic wrap. Store the tray in a warm place, watering it as needed to keep the starting mix evenly moist. Once the seedlings emerge, remove the plastic wrap and move the tray to a sunny window or place it under grow lights. Transplant the seedlings when they stand 4 inches high. Note: the seeds are highly toxic.
Sweet potato vines, as you might suspect, grow tuberous roots under the ground. You can use these roots to propagate more plants. Dig up the plant in the fall before the first frost. Brush any soil off the roots and place the roots in a warm, dry location for 2 weeks. This process removes moisture from the roots and dries the skin slightly. After 2 weeks, store the roots in straw or sawdust in a cool, dark location, such as a basement closet, over the winter. Plant the roots outside in the spring after the last expected frost. Keep the soil moist. New plants will emerge from the tuber. Cut the plants when they stand at least 4 inches high and plant them in moist, rich soil. They will grow roots and start to grow. Leave the tuber to grow more plants.
Another way to propagate sweet potato vines is through cuttings. Simply snip a few healthy pieces from the plant in the fall. The pieces should be at least 4 inches long. Remove the bottom leaves and place the cuttings in water. Store the cuttings in a sunny room but keep them away from cold windows, which will kill them. Change the water once per week. Transplant the cuttings outdoors in the spring.
Growing Sweet Potato Vine
Provided warmth and moisture, sweet potato vine is a low-maintenance, vigorous plant. In fact, the most common challenge gardeners experience with this plant is controlling its rampant growth. In containers, it spills over the sides, making a beautiful trailing plant, but it can overtake other plants growing in the container. Cut sweet potato vine back as needed to control its growth. To grow sweet potato vine in the ground, amend the soil with compost or manure to ensure good drainage. Plant the vines 1 foot apart in full sun or partial shade. You probably won’t need to provide additional fertilizer for sweet potato vines, unless growth slows and the leaves appear pale in color. Then offer an all-purpose fertilizer, according to package directions.
Sweet potato vine suffers few insect or disease pests, although it is susceptible to rust and wilt. Make sure the soil drains well and avoid getting the leaves wet. Remove any diseased portions and discard.
‘Margarita’ has chartreuse-green leaves that appear paler in shade. It grows 6 to 12 inches high and spreads 1 to 3 feet. ‘Margarita’ is among the most heat-tolerant of the sweet potato vines, but needs consistent moisture.
‘Blackie’ has large, heart-shaped leaves that come in purple to almost black. Grow ‘Blackie’ in full sun and provide consistently moist soil.
‘Pink Frost’ is an extraordinary plant. The leaves are variegated white and green and edged in pink. The plant is especially fast growing and spreads up to 6 feet in one season. It tolerates partial shade.
For more information visit the following links:
Thrillers, Fillers and Spillers from Fine Gardening
Ipomoea batatas ‘Blackie’ (Sweet potato vine) from Fine Gardening
Learn about how Sweet Potato Vine makes a great container plant on YouTube.
When she’s not writing about gardening, food and canning, Julie Christensen enjoys spending time in her gardens, which include perennials, vegetables and fruit trees. She’s written hundreds of gardening articles for the Gardening Channel, Garden Guides and San Francisco Gate, as well as several e-books.