Sweet potatoes are ideally suited for growing in places where the weather is warm and tropical. They prefer sandy soils, lots of space and sunlight, require little care, water or fertilizer, and are less likely to be attacked by diseases. They dislike nitrogen-rich fertilizers, waterlogged, heavy soil and cold weather.
Sweet potato plants provide very good and fast-growing ground cover and can be also used as living mulch to keep weeds from proliferating. Sweet potatoes are very nutritious, particularly the red varieties that are Vitamin A-rich, and just like potatoes, have as many culinary choices for preparation.
Best time to plant
Spring is the preferred time to plant. In the northern hemisphere planting in May is best, whereas it’s November in the Southern hemisphere. In cool climates a single planting is sufficient, as the plants require 4-6 months of warm weather to mature. Any time is good for planting in the tropics unless commercial growth is targeted, for which spring is best.
It’s pretty simple to start with cuttings. Start with a runner about a foot in length. First get rid of the leaves, except for those at the tip. Then plant at least two-thirds of it leaving the tip with the leaves exposed above the ground. Just like any other runner, roots will begin to sprout at every node below the earth. Even those above the ground will develop roots. Take care to space them, at least a foot apart in each row maintaining a distance of 3-4 feet between rows, as they require space for growth. To prevent weeds you need to mulch generously between plants. Once the plants grow, this is unnecessary as growth will be so fast that weeds will have no breathing space!
The other method is to use sweet potatoes from the market. Just plant them and cover with lots of soil ensuring that they remain sufficiently moist for sprouting to commence. They will soon sprout shoots, called slips. You can use these slips to grow more potatoes when they have grown to about 15 centimeters. Just snip them and plant. This way you will have plenty of plants and the original tuber too will keep on producing more slips that you can use for planting.
You can also place a sweet potato in a glass of water with its tip downward and two-thirds of the potato under water. Wait for the slips to appear. Plant these when they reach the desired length.
Where to grow
If you have gardening space, allocate a patch and prepare a raised bed as this will help drain extra water and also help the tubers to grow nice and long, without bends. Sweet potatoes also grow fast if planted under fruit trees.
Water and Fertilizer
Sweet potatoes require very little water, except at the planting stage, when you need to retain moisture for sprouting to occur. Tubers like sweet potatoes grow well with potassium and phosphorous-rich fertilizer. Using a balanced fertilizer like seaweed extract also gives good results, but compost that has a generous amount of wood ash works better. Sprinkling sulfate potash helps. Avoid any fresh fertilizer or chicken pellets. They only make leaves grow without any tubers!
If temperatures are conducive then your plants will be ready to be harvested within 4-6 months. You will be in for a pleasant surprise if you check the stem; it will have thickened. Use a fork to gently loosen the plant and you are sure to see a couple or so of sweet potatoes down there. Leaves and young shoots can be harvested anytime without affecting the tubers.
Look out for weevils, as they are prone to leave eggs in the roots and tunnel through them. Ideally prepare a patch for planting by first checking for weevils. You can avoid weevils by crop rotation, deep planting, carefully selecting clean planting materials and by getting rid of ipomoea weeds. Heaping up the soil on the plant also helps. Avoid planting in places where grasses were previously planted. Weevils can be avoided if you use cuttings and slips. When harvesting, dig up the entire crop and then plant afresh in a new bed, so that weevils are kept out.
Growing sweet potatoes is pretty easy, trouble-free and can be very satisfying.