How to Plant Sweet Potatoes in Containers

Planting sweet potatoes (Ipomoea batatas) in containers provides the freely draining conditions these vegetables love. Hardy in U.S. Department of Agriculture plant hardiness zones 9 through 11, sweet potatoes are herbaceous vines that grow 6 to 12 inches tall and spread 8 to 10 feet wide. Fungal diseases that infect sweet potatoes can live in soil, and growing the plants in a new site every year is usually recommended, but growing sweet potatoes in containers helps avoid diseases. Scrub containers for sweet potatoes with warm, soapy water before and after use.

Large containers are needed to provide room for sweet potato roots, and the plants grow well in general purpose potting soil. Sweet potato containers should be 12 to 15 inches deep and wide, and they must have drainage holes. Plastic containers are best for retaining soil moisture and are light enough to lift when harvesting the potatoes at the end of the growing season.

Place containers for sweet potatoes on special container feet or blocks of wood to allow water to drain freely from the drainage holes. Fill the containers with general purpose potting soil to 1 inch below the rim.

Plenty of light and warmth are the keys to success with sweet potatoes. Place sweet potato containers in an area of the garden that's sheltered from wind and receives at least eight hours of sunlight every day.

Sweet potatoes are frost tender and should be planted outside three to four weeks after the final local average frost date. If the weather is hot and sunny, plant sweet potatoes in the evening to avoid problems with wilting.

Sweet potatoes plants grow from shoots, which suppliers call slips. Supermarket sweet potatoes can carry diseases, so it's safest to buy disease-free sweet potato slips from a reputable supplier. The rootballs on sweet potato slips are small but grow much larger over time, and the swollen, edible storage roots develop.

Scoop a hole in the potting soil as deep and wide as the rootball of a sweet potato slip. Place the shoot in the hole so that it's growing at its original depth, and gently firm the soil around it. Multiple plants require approximately 12 inches of spacing between them and require a very large container to grow more than one plant.

Newly planted sweet potatoes don't need much water, but watering needs increase as the plants grow. Slowly pour water over the potting soil surface until it flows through the drainage holes in the containers.

Water sweet potatoes when the potting soil surface is dry. Young, small sweet potato plants can take a week or longer to use the water in their containers, but mature plants may need water every day in hot, sunny weather. Don't water sweet potatoes so much that the potting soil is soggy.