The sweet potato (Ipomoea batatas) is a dicotyledonous plant that belongs to the family Convolvulaceae.Its large, starchy, sweet-tasting, tuberous roots are a root vegetable. The young leaves and shoots are sometimes eaten as greens. Ipomoea batatas is native to the tropical regions in the Americas. The sweet potato is only distantly related to the potato (Solanum tuberosum) and does not belong to the nightshade family.
The plant is a herbaceous perennial vine, bearing alternate heart-shaped or palmately lobed leaves and medium-sized sympetalous flowers. The edible tuberous root is long and tapered, with a smooth skin whose color ranges between yellow, orange, red, brown, purple, and beige. Its flesh ranges from beige through white, red, pink, violet, yellow, orange, and purple. Sweet potato varieties with white or pale yellow flesh are less sweet and moist than those with red, pink or orange flesh.
HOW TO GROW
- Choose a sweet potato.Slips are small sprouts that are grown from pre-existing sweet potato plants. You can choose to order these online or from a garden center, but you can also grow them at home easily. Find a mature, healthy sweet potato plant from the store or a friend’s garden.
- Prepare your potato.When you’ve gotten your hands on 1-2 healthy sweet potatoes, stick them in the sink and wash them well. Then, cut your potato in half. If the potato is particularly large, consider cutting it into thirds or fourths.
- Fill a jar with water.The way your slip-growing works, is that you’ll place your potato half in/half out of a container of water. Use a jar or a glass cup with an opening large enough to fit your potato, and fill the whole thing with water.
- Place your potato in the water.Stick 4-5 toothpicks out of the sides of your potato equidistant apart and near the middle, like spokes on a wheel. Place the potato into the jar/glass of water with the cut side down, with the toothpicks holding half of the potato out by balancing it on the rim of the glass.
- Do this for every slice of potato that you have, with each section in a different jar.
- Add some light and heat.Move the jar with the potato onto a windowsill that gets a lot of sunlight.
- Let your slips grow.Wait for 2-4 weeks for the small leafy slips to begin sprouting out of the top of the potato.
- Harvest the slips.When the top of your potato is covered in slips, carefully twist each one off individually. They won’t have roots yet and will resemble small leaves with a short stem.
- Put your slips in water.Fill a shallow bowl with a bit of water, around 1” or less depending on the number of slips you have. Set the slips in the bowl so that the stem is submerged in the water. Leave them like this for several days, until roots have formed from the bottom.
- Add fresh water once a day or so to keep the slips healthy.
- If any of the slips are not forming roots or begin to wilt, throw them out.
- Get your slips out for planting.After 2-3 days, your slips should have developed roots at the bottom. At this point, dump out the water in the bowl and bring your slips out for planting. These are best placed directly into your garden rather than in individual planters to keep the roots intact.
- Choose a garden plot.Sweet potatoes grow primarily underground, so they don’t need much garden space. However, they prefer a warm environment, so try to choose an area that gets a lot of sunlight (especially if you live in the north) and is well drained.
- Till the earth.Being tubers, sweet potatoes will grow deep in the earth. Make sure they’ll have an easy time of it by tilling the soil about 12 inches (30.5 cm) deep. Get the soil as loose and light as possible, incorporating gardening soil if necessary.
- Prepare the soil.As will all fruit and vegetable planting, having nutrient rich soil is necessary for a bountiful harvest. Add a layer of good planting soil and remove any large rocks that might be present. Check the pH of your soil, and peat moss or wood ash to compensate for acidity or alkalinity to create a neutral pH.
- Know when to plant.Because of their heat-loving tendencies, sweet potatoes need to have warm soil in order to flourish.
- Choose a mulch.Help your sweet potatoes to grow by adding mulch over the top to trap heat. If you are in a particularly cold area, get some black plastic mulch or a similar heat-trapper to place over the potato plants after planting.
- Dig your holes.Sweet potato slips need a bit more space than some other garden vegetables, so dig your holes 12–24 inches (30.5–61.0 cm) apart each. They need be only as deep as the root ball on the bottom of the slips and about ½ an inch up the base of the plant.
- Plant your potatoes.Place each small slip in your pre-dug holes and cover the stems with soil about ½ of an inch up the base. The leafy part of the potato plant will begin to sprawl in vines outwards while the roots will produce the tubers between 6–12 inches (15.2–30.5 cm) deep in the soil.
- Add your mulch.Protect your sweet potatoes from cold weather by adding your chosen mulch to the top. This will also help to block out weeds and prevent too much vine growth, which steal energy from tuber growth.
- Water the plants.At first planting the sweet potatoes will require a lot of water. Over time, you should reduce the amount that you water them until they receive moisture only about once a week. Begin watering daily, knocking off days from your watering schedule as each week progresses.
- Wait for the tubers to develop.Sweet potatoes have a relatively long fruiting period, becoming ripe and ready to harvest in the early fall (hence their association with Thanksgiving). Continue watering on a weekly basis, and weeding the beds if necessary to keep the plants healthy.
- Harvest the sweet potatoes.After about 120 days after planting, the sweet potatoes should have reached full maturity. When possible, wait until the last possible time (the last warm weather before a frost) to harvest the sweet potatoes, as this will result in larger and more tasteful tubers.
- Side-dress the potatoes 3 to 4 weeks after transplanting with 1.5 Kg of 5-10-10 fertilizer per 100 feet of row. If you have sandy soil, use 2.25 Kg.
- Hoe the beds occasionally to keep weeds down. Remember to reshape the beds with soil or mulch.
- For good harvests, do not prune the vines, because they should be vigorous.
- Remember to keep the potatoes watered. Deep watering in hot, dry periods will help to increase yields, although if you are planning to store some of the potatoes, do not give the plants extra water late in the season.
- Leaves become yellow or brownish, wilt and droop, brown to black steaks inside stems; plant become stunted.Fusarium wilt is a fungal disease which infects plant vascular tissues. Fungal spores live in the soil and can be carried by cucumber beetles. Plant disease-resistant varieties. Rotate crops. Remove and destroy infected plants. Fungicides are not effective.
- Water-soaked blotches on leaves–not enlarging past leaf veins.Leaf spot or bacterial spot is a waterborne bacterium which causes irregular geometric patterns on leaves. Spots may turn yellow and crisp. Avoid wetting foliage with irrigation. Prune off infected leaves and stems. Clean up garden. Plant disease-resistant varieties. Rotate crops up to 2 years.
- Small shot-holes in leaves of seedlings.Flea beetles are tiny bronze or black beetles a sixteenth of an inch long. They eat small holes in the leaves of seedlings and small transplants. The larvae feed on roots of germinating plants. Spread diatomaceous earth around seedling. Cultivate often to disrupt life cycle. Keep garden clean.
- Holes in leaves and roots.Larva of sweet potato weevil is a white, legless grub with a pale brown head about 3/8 inches long; the adult beetle has a reddish snout. The grub will tunnel through leaves and roots. Pick off weevils. Remove and destroy infested plants. Sprinkle plants with diatomaceous earth. Cultivate the planting bed before planting to disturb the weevil’s life cycle.
- Leaves turn yellow and then brown from the bottom up; plant loses vigor; cracks in roots.Root knot nematode is a microscopic eelworm that attacks roots. Plant resistant varieties. Rotate crops. Remove old plant debris from garden. Root cracks also can be the result of too sudden uptake of water; keep watering even; avoid dry and wet spells.
- Sweet potatoes are considered low on the glycemic index scale, and recent research suggests they may reduce episodes of low blood sugar and insulin resistance in people with diabetes.
- Maintaining a low sodium intake is essential to lowering blood pressure, however increasing potassium intake may be just as important. According to the National Health and Nutrition Examination Survey, fewer than 2% of US adults are meeting the daily 4,700 mg recommendation for potassium. One medium sweet potato provides about 542 milligrams.
- Among younger men, diets rich in beta-carotene may play a protective role against prostate cancer, according to a study conducted by the Harvard School of Public Health’s Department of Nutrition.4 Beta-carotene has also been shown to have an inverse association with the development of colon cancer in the Japanese revision.
- The antioxidant vitamins C and E in sweet potatoes have been shown to support eye health and prevent degenerative damage.
- A higher intake of all fruits (3 or more servings per day) has also been shown to decrease the risk of and progression of age-related macular degeneration