Sweet potatoes are so eager to grow you can practically drop one on the ground and it’ll spring up if covered with a little warm soil. That may be a bit of an exaggeration but sweet potatoes are great backyard plants provided you live in a warm area or can keep the soil toasty for the 4 months they need to grow. Other than that, they do not need much care beyond a little water, space and time. Here’s how to grow sweet potatoes in a few easy steps.
Like most any vegetable, sweet potatoes come in dozens of varieties. They vary in shape, color, texture and flavor but most importantly in hardiness. Some sweet potatoes may be more suited to your growing zone than others. “Georgia Jet” is a popular short season variety of sweet potato. It’s best to consult local growers to see which variety does well in your area, particularly if you are trying to grow in a cooler climate.
When To Grow
Sweet potatoes like it hot. This sets them apart from regular potatoes, which tend to like cool soil. Plan to plant your sweet potatoes about a month after the last frost of the winter. If you live in grow zones 3 or higher, you will need to warm the soil in order to plant by June, otherwise you will not have enough time for them to mature before it gets too cold again. Most varieties of sweet potato need 100 – 140 days to mature.
Where to Grow
Sweet potatoes grow best in hot, tropical climates. They are known as a southern crop but can be grown in northern zones (even in Canada!) but will need some assistance. They are best grown where temperatures are at least 70° F but 90° F – 100° F is even more ideal, at least for the hotter parts of the growing season.
Sweet potatoes need lots of space and are best suited for an area of the garden that has sandy soil. Each plant will need at least 1 foot of space to itself (3 feet between rows) and sweet potatoes grown in heavier clay soil should be in raised beds and amended with lots of compost and sand. Choose a spot that gets full sun exposure, but if you live in an extremely hot and sunny climate, you may need to shade young seedlings during the hottest part of the day.
Best Soil For Growing Sweet Potatoes
Sweet potatoes will do best in loamy, sandy soil. Though they can tolerate heavier soil, it should be fortified with plenty of mature compost and some sand. Add an inch layer of compost to even the loamiest of soils to give the sweet potatoes a fertile boost right from the start, though they don’t need particularly rich soil to thrive. The most important thing is that the soil drains easily and is well aerated. Test the soil to be sure the pH is about 5.8 – 6.2, though sweet potatoes can stand a slightly acidic soil up to 5.0.
Unlike regular potatoes that can be grown from pieces of mature potatoes, sweet potatoes are grow from rooted sprouts called “slips.” Slips can be purchased from a reputable nursery or by mail order.
If you’re growing in a cooler zone of the north, it’s a good idea to cover the soil with clear or black plastic about 3 weeks before planting. This will help warm the soil to a suitable temperature. Clear plastic will allow most of the sun’s energy to pass into the soil and then keep it there. Black plastic may draw more sun but will hold onto much of it. It’s easier to defeat weeds with black plastic mulch but clear plastic will work just fine if stretched snug against the soil with slits for the sweet potato plants only.
Space each sweet potato slip about 12” apart in rows 3 feet apart. Moisten the soil and add some mature compost to each hole before planting. Bury each slip stem up to the first set of leaves.
Watering & Care
Water sweet potatoes regularly, weekly and deeply during long dry spells. Too much water will slow their growth, but shouldn’t kill them. Like most vegetables, try to keep the soil consistently moist without getting it muddy or letting it dry out completely.
Carefully weed your sweet potato patch about 2 weeks after planting. Use mulch if necessary to help keep the weeds down. This will also help maintain moisture and warmth in the soil.
Sweet potatoes are known to produce with little to no feeding. However, they will benefit from a light feeding about 2 weeks after planting. Use a balanced organic fertilizer that contains potassium. A compost tea can work well too.
Harvest & Curing
Sweet potatoes will not exactly mature in the fall but they will stop producing when temperatures drop to about 55° F. This is a good time to dig up all of your tubers. Wash them immediately.
Sweet potatoes need to be cured before eating them. A freshly “picked” sweet potato will not taste like it should. Cure the sweet potatoes by keeping them warm (85° F – 90° F) for five days or at slightly cooler temperatures for 10 – 15 days. They will develop a thick second skin that will preserve them for a few month. Store them in a well-ventilated space for at least a month before eating. Storing temperatures are best around 60° F.
Tips & Advice
Sweet potatoes bruise easy even if they feel tough.
Do not store sweet potatoes in plastic containers or zip lock bags. They need to breath. They will also not tolerate the cool of the refrigerator. They are a tropical plant; just keep them on the counter top.
Do you have tips on how to grow sweet potatoes? Let us know in the comments section below!