Learning how to grow sweet potatoes is surprisingly easy – just a few plants provide a plentiful harvest. Sweet potatoes need a long warm growing season, are heat tolerant and drought resistant, and have very few pests or diseases. All of this makes them perfect for growing in the low desert of Arizona (yay!) Here are eight tips for how to plant, grow, and harvest sweet potatoes.
8 tips for growing sweet potatoes
2. Prepare soil correctly before planting sweet potatoes
3. Plant sweet potato slips
Sweet potatoes aren’t grown from seed like many other vegetables, they are started from slips – rooted sweet potato shoots grown from a mature sweet potato. Grow your own slips from sweet potatoes or purchase slips.
Most varieties do well in the long growing season of the low desert. In higher elevations or places with shorter growing seasons, choose from quickly maturing varieties such as ‘Beauregard’ and ‘O’Henry’.
Plant rooted slips 12-18 inches apart and 4 inches deep. Water well and feed with a starter solution high in phosphorus to ensure the plants root well.
4. Fertilize once and do not prune vines
About a month after planting sweet potatoes, fertilize with an organic fertilizer with phosphate and potassium to encourage more root development.
Occasional small harvests of greens to eat is fine, but do not prune back vigorous vines for the best-sized harvests. The size of the sweet potatoes is determined by the amount of sunlight the leaves receive. More sunlight and leaf surface area that receives sun means larger sweet potatoes.
If space is an issue, consider growing vines vertically up a trellis to allow sunlight to reach the leaves and produce larger sweet potatoes.
5. Water deeply and regularly
Deep watering is crucial for sweet potatoes during hot dry periods. Let soil dry out somewhat between waterings.
6. Harvest sweet potatoes at the right time
Here are a few things to look for before harvesting sweet potatoes:
- Sweet potatoes are ready to harvest between 90-120 days after planting
- Harvest when tubers are at least 3 inches in diameter
- Harvest sweet potatoes before the first fall frost
- Usually sweet potatoes are ready to harvest when the leaves and vines begin turning yellow
7. Harvest sweet potatoes correctly
Once you have decided to harvest the sweet potatoes, cut back vines and loosen soil around the plant with a spade fork. Carefully find the primary crown of each plant, and use your hands to dig up the tubers. Shake off any excess dirt, and handle tubers carefully to prevent bruising.
8. Cure sweet potatoes before storing
To cure sweet potatoes, set potatoes in a single layer (not touching) in a warm (about 80℉) dark area for 10-14 days. Curing allows cuts and bruises to heal. After curing, throw out or immediately use any bruised potatoes. Store cured sweet potatoes in a cool (about 55-65℉) dark area for up to 6 months.