HOW TO GROW SWEET POTATO

SWEET POTATO (Impomea batatas) are popular tubers grown in most ASEAN Countries. The part we eat is the tuberous root of this warm-weather perennial vining plant. The edible sweet potatoes are closely related to morning glories (Ipomoea tricolor) and are the same species as the sweet potato vining plants commonly grown as ornamentals. The edible and ornamental types are different cultivars of Ipomoea batatas. Although the terms sweet potato and yam are used interchangeably in the Malaysia and other Asean States they are two entirely different vegetables. They are also unrelated to regular potatoes. The orange-fleshed sweet potatoes are the most familiar, but sweet potatoes can be white, yellow, and even purple. Sweet potatoes are slow-growing and are always planted in spring because they require four months of warm temperatures to develop full-size tubers, but they are surprisingly easy to grow. Since the vines root wherever they touch the ground, a few plants can produce a generous harvest. There are also bush varieties, for smaller gardens. In the blog ''Anim Agriculture Technology'' I write about how to grow sweet potato.

Growing sweet potatoes grown for consumption are usually planted from purchased slips small rooted pieces of a tuber or from tubers that you root at home. You can try growing sweet potatoes from the grocery store, but the only way to be certain you have certified disease-free roots is to buy slips from a reputable seed supplier. Plant slips about 12 to 18 inches apart with 3 to 4 feet between rows. The vines will spread and fill in, so give them plenty of room. Sweet potatoes will generally thrive in any average well-drained soil in a sunny location. These plants are tropical in origin, so wait until the soil has warmed up fully before planting. If your soil is too dense or rocky, consider planting sweet potatoes in raised beds filled with a sandy but rich potting soil. To give them a head start, sweet potatoes are often planted in raised rows, about 8 inches high. This helps the soil warm faster and keeps them well-drained. If you are gardening in a cooler climate, spreading black plastic on the soil will also help it warm faster.  Keep the plants moist, especially during dry spells. Three to four months after planting, the tubers should be ready to harvest for eating. For sweet potato agronomic practices need light in full sun to part shade. They generally prefer full sun but appreciate some afternoon shade in hot, dry regions. For soil requirement sweet potatoes prefer soil that is well-drained but high in organic matter and for sandier soil is preferable to be a dense clay soil. Once established, sweet potatoes will tolerate growing in dry soil. It's best to keep it evenly moist with 1 inch of water given once a week. Don't water your sweet potatoes during the final three to four weeks prior to harvest to prevent the mature tubers from splitting. Sweet potatoes should not be planted outdoors until the temperature of the soil has warmed to 29.5 Celcius. Sweet potato  need soil growing temperatures between 60 to 85 degrees Fahrenheit and an air growing temperature of 65 to 95 degrees Fahrenheit.

Sweet potatoes are not heavy feeders, but it's important to give them balanced nutrition, typically with proper soil preparation. Overfeeding tends to promote growth of foliage rather than tubers. The best approach is to add compost to the beds before planting the sweet potatoes. Alternatively, you can apply an organic liquid fertilizer to the soil prior to planting. In Malaysia there are few commercial sweet potato grown by farmers such as Bukit Naga, Vitato, Keledek Bikam, Jalomas and few others. Sweet potato tubers are ready to harvest in about three to four months, depending on the cultivar. If there are demand to eat the leaves as greens, you can do so in moderation throughout the season. Be sure to leave enough to keep the plant growing. To harvest is by digging up the tubers once the foliage starts to yellow.  Ensure do not let them sit in the ground too long after the tops die back or they could start to rot. Be gentle when digging. Sweet potato tubers grow close to the surface. Their skins are tender and can be damaged and bruised easily. Dig up the tubers using cangkul and collect the tubers for grding. Divide them into pieces, making sure that each piece has at least one eye. Plant them in the garden after the threat of frost has passed and the soil temperature is at least 15 degrees Celsius. Wireworms and root-knot nematodes are the biggest problems when growing sweet potatoes in home gardens. Damage is lessened if you rotate your crop each year. Many diseases can be avoided by choosing disease-resistant varieties and using certified disease-free sweet potato slips. Rotating their location in the garden from year to year also helps. Mice can also be a problem, so be on the lookout. Thanks...

By,

M Anim,

Putrajaya,

Malaysia.

January 2021.

Updated May 2025.