Sweet potatoes are a versatile and nutritious addition to any garden, and they come in two main varieties: vining and bush. Both types thrive in the hot summer sun and are relatively easy to grow if you provide the right conditions.
Unlike most vegetables, sweet potatoes aren't grown from seeds but from slips. Slips are shoots grown from a mature sweet potato. In this guide, I'll walk you through the steps to grow, harvest, and cure your own sweet potatoes.
Step 1: Start the Slips
You can order slips from an online catalog or start them yourself from a sweet potato purchased at the store or from your garden. If you’re using store-bought sweet potatoes, check if they are a bush type or a vining type. Bush types are shorter but still have a vining nature.
To start your slips, select several healthy, clean sweet potatoes. Each sweet potato can produce up to 50 slips. Wash the sweet potatoes thoroughly and cut them in half or into large sections. Place each section in a jar or glass of water, with half of the sweet potato submerged and half above water. Use toothpicks to hold the sweet potato in place. Place the jars on a warm window ledge or atop a radiator. Within a few weeks, the sweet potatoes will sprout leafy shoots on top and roots on the bottom.
Step 2: Root the Slips
Once your sweet potatoes have sprouted, separate them into individual slips. Gently twist each sprout off the sweet potato and place it in a shallow bowl with the bottom half of the stem submerged in water. The leaves should hang over the rim. In a few days, roots will form at the bottom of each slip. They are ready to plant when the roots are about an inch long. Keep the water fresh and discard any slips that aren’t rooting or appear wilted.
Step 3: Prepare the Soil
Sweet potatoes require loose, well-drained soil to grow large tubers. The soil should be free of obstacles that might impede root expansion. Proper soil preparation is crucial for a successful sweet potato harvest.
Step 4: Plant the Slips
Plant the slips in the prepared soil, with the roots pointing downwards. Cover the bottom half of each slip with soil, leaving the top half with the leaves exposed. Be gentle to avoid bruising the young plants. Firmly press the surrounding soil to eliminate air pockets. Continue this process until all slips are planted.
Spacing Note: Sweet potato plants spread quickly and root at leaf nodes. Bush types may grow up to 3 feet long, while vining types can extend up to 20 feet. Space your plants 12-18 inches apart to accommodate their growth.
Step 5: Watering
Immediately after planting, water the slips thoroughly. New plants need to be watered daily for the first week and every other day the second week. Gradually reduce the frequency until you’re watering once a week. Adjust based on soil dryness and weather conditions. Sweet potatoes can tolerate drought but will yield less, so ensure they receive adequate water during hot summer months.
Step 6: Harvest
The time to harvest sweet potatoes depends on the variety. Most varieties take about 90 to 120 days to mature. Some newer varieties, bred for short-season climates, may mature faster. Regardless of your location, harvest before any frost or freeze. In northern gardens, harvest when nighttime temperatures drop to 40-30°F to avoid frost damage.
In southern gardens, aim to keep sweet potatoes in the ground for the full 120 days, as frost is less of an issue. Unlike white potatoes, sweet potatoes don’t show signs of readiness by dying back. They continue to grow until halted by frost.
When harvesting, choose a dry day. Use a shovel or pitchfork to gently lift the soil and avoid damaging the sweet potatoes. Minor damage can lead to spoilage, so handle them carefully.
Step 7: Cure the Sweet Potatoes
After harvesting, cure your sweet potatoes to enhance their flavor and shelf life. Let the freshly dug sweet potatoes dry in the sun for a few hours. Then, store them in a box lined with newspaper in a well-ventilated area for a couple of weeks at 85-90°F.
Next, move the sweet potatoes to a cooler location (55-60°F) with 75-80% humidity, such as a root cellar. Check them regularly for spoilage and discard any affected sweet potatoes. Properly cured sweet potatoes can be stored for several months.
By following these steps, you can enjoy a bountiful harvest of sweet potatoes, perfect for various culinary uses throughout the year. Happy gardening!
