How to Grow and Care for Sweet Potato Vine

Ornamental sweet potato vines are a classic "spiller" plant perfect for container gardening. They are cultivars of the same species as edible sweet potatoes but are only ornamental, not edible, as they are very bitter. This beautiful, fast-growing tender herbaceous perennial is native to tropical regions of the Americas and best planted in the spring once temperatures consistently stay about 50 degrees Fahrenheit. It has long tendrils that tumble over the edges and down the sides of containers. Sweet potato vines are available in various colors—from almost black to chartreuse—and with several different leaf shapes. They are bred for the beauty of their leaves rather than their edible tubers, and the vines from these plants make them look more like morning glory or clematis.

Botanical Name	Ipomoea batatas
Common Name	Sweet potato vine, ornamental sweet potato vine
Family	Convolvulaceae
Plant Type	Herbaceous perennial
Mature Size	8–10 ft. long, 5–12 in. wide
Sun Exposure	Full sun
Soil Type	Moist, well-drained
Soil pH	Neutral to acidic
Bloom Time	Spring, summer
Flower Color	Rarely flower but may produce pink to purple-lavender
Hardiness Zones	9–11 (USDA)
Native Area	Tropical regions of the Americas

Sweet Potato Vine Care

Ornamental sweet potato vines are versatile plants that are equally suitable for filling outdoor containers, spilling over a wall, or covering ground in a landscape bed. They are also popular as indoor plants and can be grown inside year-round or just during winter. Like many rooting vines, they can be vigorous growers in the right conditions and may need frequent trimming to stay in check. The parts you trim back can be used to propagate the plant elsewhere.

The plant grows best at an average temperature of 75 F and does not tolerate frost. It prefers sunny days and warm nights. The plant is drought-tolerant but likes its water. Do not allow this plant to get waterlogged. Sweet potato vines rarely flower when the daylight is longer than 11 hours, which normally occurs outside the tropics.

Light

Sweet potato vines love the sun but will also grow in partial shade and sometimes full shade. The more sun the plant gets, the more vibrant its leaf color will typically be.

Soil

These plants prefer moist, well-drained soil that's nutritionally enhanced with organic matter. They are prone to root rot if their soil remains too wet. Make sure that the container you choose has ample holes for drainage.

Water

Sweet potato vines are drought-tolerant, though they will grow more vigorously with frequent watering. Water enough to keep the soil consistently moist but not overly wet. Its leaves will wilt when the plant is thirsty.

Temperature and Humidity

These vines like sun more than high heat. In hot climates, they will benefit from some shade, and they should be watched carefully, so their soil doesn't dry out. They thrive in many humid climates but don't need high humidity as other tropical plants do.

Fertilizer

Fertilize sweet potato vines if you want them to grow vigorously. A weekly feeding with a well-balanced fertilizer during their growing season will boost growth, but given their naturally robust habit, you may find that feeding also increases the need to cut them back.

Types of Sweet Potato Vine

• Ipomoea batatas ‘Sweet Caroline’: Popular as a ground cover, this varietal is available in five different colors, including light green, yellow-green, bronze, purple, and red. Additionally, its leaves are shaped somewhat like maple leaves.
• Ipomoea batatas ‘Margarita’ or ‘Marguerite’: This varietal sweet potato vine is mounding but can be trained as a climber. Its foliage is a bright, light green, or chartreuse when grown in full sun, and darker green if grown in shadier locations.
• Ipomoea batatas ‘Blackie’: Dark purple, maple-like leaves; sometimes flowers with purple, trumpet-shaped blooms
• Ipomoea batatas 'Ragtime': One of the varieties with narrow, divided leaves; its coloring is a pale purple with some attractive natural variation

Pruning

Use bleach or rubbing alcohol to sterilize a pair of pruning shears between the pruning of different plants. Remove broken or sickly vines. Cut back vine tips that have exceeded their boundaries. Cut about 1/4 inch above leaf nodes to encourage new growth. The more the vine that is pruned, the more it will try to regrow.

Propagating Sweet Potato Vines

Sweet potato vines are easy to grow from existing plants. Cutting is the best way to propagate, but you can also plant the plant's tubers in the spring.

To propagate with cuttings:

1. If you live in a place that gets wintery weather, you'll want to take a cutting from your outdoor sweet potato vines in the autumn before the first frost. The plant dies off when exposed to frost. You'll need pruning shears or snips, a jar of water, and a sunny spot.
2. Using clean, sharp garden pruning shears, cut off a branch that has several leaf nodes. Remove the leaves off of the bottom few inches.
3. Submerge the stem in water. In a few days, the plant will grow roots. 
4. The plant can live indoors in water in a sunny spot throughout the winter. Keep the water level constant. Empty the water and refill the jar with clean water every week to discourage bacterial growth.
5. Come springtime after the last frost, you can replant it in the garden in moist, well-draining soil in a sunny spot outdoors. Harden off the plant before placing in the garden to acclimate it to outdoor conditions.

To propagate using its tubers:

1. Sweet potato vines produce tuberous roots. You can save the tubers for the next season. You'll need a box, peat, or vermiculite, and a cool, dry place, such as a basement, crawlspace, or root cellar.
2. Dig up the tubers before the first frost, let them dry. Bury them in peat or vermiculite. Do not let them touch.
3. In spring, the tubers will sprout. Inspect the tuber for signs of disease or infection. You'll need a clean, sharp, non-serrated knife. Cut off and discard any blackish areas, visible wounds, puckered spots, or discoloration. Divide the tuber using the sterile knife, making sure each tuber has at least one eye and some shoots or roots. Plant them after the last frost in moist, well-draining soil, 2 inches deep at least 2 feet apart in a sunny spot.

How to Grow Sweet Potato Vine From Seed

Sweet potato vines are rarely grown from seeds, since they can grow from cuttings and their tuberous roots. Also, since it doesn't flower reliably, you can't always get seeds. Many varieties are sterile.

1. Presoak seeds for 12 hours in warm water to help with germination.
2. Fill a seed-starting tray with a light, soil-less starting mix. Sprinkle the seeds over the tray, spacing them 3 inches apart. Cover them with a light dusting of starting mix.
3. Spray the mix with water from a spray bottle and cover the tray with plastic wrap or a humidity dome.
4. Store the tray in a warm place. Keep the starting mix evenly moist
5. Once you see seedlings, remove the plastic wrap and move it to a sunny window or under a grow light.
6. Sweet potato vines dislike root disturbance, so transplant immediately after sprouting or grow in biodegradable pots.
7. Harden off seedlings before transplanting it in the ground or outdoor container.

Overwintering

Cutting is a good way to overwinter sweet potato vines because they will last all winter in the water and be ready to plant in the spring. Another way to overwinter sweet potato vine is to dig up the sweet potato vine's tuberous roots and store them in a cool, dry space in peat or vermiculite. Come spring, you can plant the sprouting tuber.

Common Pests and Plant Diseases

The golden tortoise beetle likes to feast on sweet potato vines. The insect looks like a teardrop of molten gold. While interesting to look at, the beetle will munch holes in the leaves, making them look like Swiss cheese. Aphids also favor sweet potato vines.

Depending on where you live, other common pests include the sweet potato looper, a caterpillar that chews on the leaves; the sweet potato whitefly, which can drain the plant of nutrients and stunt its growth; and sweet potato weevils can cause yellowing of the vines.

Sweet potato vines are also prone to leaf fungus, particularly if they are planted in the same place for multiple seasons. Minimize this problem by varying the planting locations from one season to the next. The most common soil-borne fungi are verticillium or fusarium. If you notice the plant yellowing at the base and working its way up the plant, it can be a fungal infection.

How to Get a Sweet Potato Vine to Bloom

Sweet potato vines rarely bloom, but when they do, they're glorious. And, they look like trumpeting morning glories too. They do not have a scent. They need perfect conditions in the spring or summer months to flower, and that often means sufficient water—moist, but not waterlogged—ample sun, and a good nutritional balance. Although a low-nitrogen, bloom-enhancing fertilizer with a ratio of 7-9-5 will best support flowering, you can also use a balanced fertilizer. Pluck off spent flowers to encourage more flower growth.

Common Problems With Sweet Potato Vine

This plant is prone to pests and diseases that are often the cause of browning or blackening of leaves, wilting, and ultimately, death.

Leaves Turning Yellow or Brown

Root rot and fungal infection may cause sweet potato vines to develop yellow or brown leaves that wither and drop. To prevent root rot, plant in containers with drainage holes and keep well-draining soil evenly moist but not waterlogged.

Fungal infection can be prevented from reoccurring the following year by planting it in another location next season. However, in the current growing year, a fungus-infected plant is not salvageable. It's best to pull the infected plants to prevent the spread to other nearby plants.

To prevent disease, plant sweet potato vine with space to spread and air to circulate the plant. If its soil pH, nutrition, sun exposure, and water needs are met, it can fight off disease more readily.

Blackened Leaves

Sweet potato vines are frost-sensitive. Blackened or mushy leaves can indicate that the plant got frostbite. Pull it up and discard it.

Leaves Wilting or Curling

Keep its soil consistently moist. When watering sweet potato vine, water the soil to a depth of 6 inches. Sweet potato vines will wilt or curl their leaves when lacking water.

Holes in Leaves

Holes in leaves are the sign of an insect feasting on your sweet potato vine, likely tortoise or flea beetles. To get rid of beetles, shake them off into a bucket of soapy water. Spread diatomaceous earth around the plant. You can also apply neem oil to the affected area. Use a plant-based pyrethrin insecticide but only as a last resort since it will also kill beneficial insects.