How to Grow Sweet Potatoes? A small number of sweet potato plants can yield a large harvest of this nutritious, sweet-tasting root vegetable. Although they are usually produced in the South because of their need for warm temperatures, northern regions can have success with certain kinds. Discover how to plant, care for, and harvest sweet potatoes, as well as the best types.
About Sweet Potatoes
Sweet potatoes are tropical plants that belong to the morning glory family. Compare the foliage and blossoms of a sweet potato vine to those of morning glory and you’ll see the family resemblance! They are not related to potatoes, which are members of the nightshade family. Another distinction between sweet potatoes and “regular” potatoes is that the sweet potato’s edible section is a tuberous root rather than a real tuber (which are technically modified plant stems).
This root vegetable has a coppery skin covering and vivid orange meat. Sweet potatoes are frequently served mashed or roasted whole. They can also be used as a pie filling.
This tropical crop requires at least four months of warm weather and soil, yet it is drought and heat tolerant, with few pests and illnesses. Although sweet potatoes were traditionally a Southern crop, there are now numerous short-season cultivars available. They will grow in the north (even portions of Canada!) if cultivated in sandy soil or raised beds with black plastic mulch to keep the soil warm.
How to Grow Sweet Potatoes?
Select a sunny location with well-drained soil. Sweet potatoes aren’t choosy, but they do prefer a sandier soil. They require enough of air space in the soil for their roots to grow. Consider planting on raised beds if your soil is clay, rocky, or compacted.
Compost, perlite, and/or coconut coir should be added to the growing area to create healthy, loamy soil down to 8 to 10 inches. Animal dung, including pelleted chicken manure, should be avoided since it can cause spindly and/or discoloured roots. Avoid using high nitrogen fertilisers, which encourage luxuriant leaf development at the price of tasty roots!
- Plant slips outside 3 to 4 weeks after your last spring frost, or when the soil temperature has reached at least 65°F (18°C). Temperatures at night should be at least 55°F (13°C). The trick is to plant them early enough to allow them to fully mature, but not too early that they are killed by a late April frost.
- Because immature sweet potatoes are highly fragile, keep them away from late frosts or cool nights (lower than 55°F/13°C). Cover them with plastic milk bottles or row covers, then remove them during the day.
- If you ordered slips through the mail, unpack them as soon as possible. Put the roots in water for a day or two to liven them up. Plant them as soon as the weather permits.
Plant Sweet Potatoes:
- Make raised mounds. 6 to 8 inches tall and 12 inches across.
- Plan 3 feet between mounds to give vines enough room to grow.
- Plant the slips on a warm, cloudy day when the soil temperature is 60°F (15°C).
- Remove the bottom leaves, leaving only the upper ones.
- Set the slips deep enough to cover the roots, stem, and leaves. On the nodes, sweet potatoes will grow.
- Water generously for 7 to 10 days after applying a high-phosphorus liquid fertiliser to ensure that the plants root effectively.
- Side-dress the sweet potato plants with 5-10-10 fertiliser 3 to 4 weeks after transplanting. Use more if you have sandy soil.
- Weed the sweet potato beds on a regular basis beginning two weeks after planting.
- Deep digging with a hoe or other equipment that disrupts the delicate feeder roots should be avoided.
- Water on a regular basis, especially during the summer. Deep watering during hot, dry spells will assist plants boost yields.
- Sweet potato vines should not be pruned; they should be strong.
- Reduce watering late in the season to avoid cracking of the sweet’s skin, which can occur during storage.
- As soon as the roots are large enough to eat, you can begin digging them up.
- Harvest when the leaves and ends of the vines begin to turn yellow, or approximately 100 days after planting.
- To avoid harming the roots, loosen the soil around each plant (18 inches around, 4 to 6 inches deep). Remove some of the vines.
- Pull up the major crown of the plant and dig up the roots by hand. Handle the sweet potatoes with care because they bruise easily.
- Remove any excess dirt by shaking it off; do not wash the roots.
- Harvesting should be completed by the first fall frost.
4. Wit and Wisdom
- Sweet potatoes are an extremely healthy root vegetable with numerous health advantages. Here are some reasons why you should eat sweet potatoes.
- They were used to treat asthma, night blindness, and diarrhoea in folk treatments.
- Sweet potatoes are not to be confused with yams, which are linked to grasses and lilies. They are also unrelated to conventional white potatoes, which are members of the nightshade family rather than the morning glory family. As previously stated, the edible component of potatoes is a real tuber, whereas sweet potatoes have tuberous roots.
4. Pests and Diseases
When cultivating sweet potatoes in a home garden, the most common pests are wireworms and root-knot nematodes. 1 Crop rotation reduces damage. Choosing disease-resistant types and utilising certified disease-free sweet potato slips will help you prevent many diseases. Mice can also be an issue, so keep an eye out for them.
Best Soil For Sweet Potatoes
Is this your first time cultivating sweet potatoes, or did you struggle with them last year? If this is the case, you are not alone. Many gardeners are curious about the optimum soil for growing sweet potatoes. Using the proper sweet potato soil will result in a significantly larger harvest in the fall.
Sweet potatoes thrive in loose, warm soil that drains easily (for example, sandy loam soil). Sweet potato soil should have a pH of 5.5 to 6.5. Improve sweet potato growth by adding organic material to your soil (such as compost or aged manure). Don’t worry if your soil does not perfectly suit the profile stated above; there are ways to enhance it. Let’s talk about what kind of soil you’ll need to grow sweet potatoes and how to prepare your soil for them.
1. Soil Consistency
If the soil in your garden adheres together readily and can be moulded into shapes (like clay), you have clay soil. Clay soil has very small particles and holds water because it drains slowly. Clay has very closely packed particles, making it a dense soil. Sweet potato tubers grow underground, thus clay soil will make it difficult for them to grow.
To add organic material to clay soil, mix in some compost or old manure. This loosens the soil, allowing it to drain more quickly. Compost will also enrich the soil with nutrients. If your garden soil is loam (not clay), yet it is too dense, add some sand to soften it out. Remember not to mix sand with clay soil. You will receive very hard soil that will be difficult to work with!
Sweet potatoes, potatoes, carrots, and other crops with subterranean roots or tubers thrive considerably better in loose soil. These crops may grow freely in loose soil because they are not hampered by dense clumps of soil. If your garden soil is highly sandy, it will drain quickly – potentially too quickly. This can result in water shortages for any plants you try to cultivate, regardless of how much you water them.
If your soil is light, crumbles readily, and dries quickly, it is most likely sandy soil. Sifting the soil improves its texture regardless of the type of soil you have in your garden. A soil sifter removes particles (such as roots, rocks, and soil clumps). A dirt sifter made of wood, nails and rabbit wire with small holes can be made. If you don’t want to build one, you can buy a soil sifter online.
2. Soil pH and Nutrients
Sweet potatoes grow best on soil with a pH of 5.5 to 6.5. (somewhat acidic to slightly acidic). If you are unsure about the pH of your soil, conduct a soil test. Home soil test kits are available online or at garden supply stores. You can also send a sample of your soil to a local agricultural extension organisation for analysis. If you want to understand more about these soil testing alternatives, I’ve prepared an essay about it here.
A soil test will disclose the pH of your soil as well as how much of each nutrient is present. Nitrogen, phosphorous, and potassium (commonly known as NPK, or the “big three”) are the most crucial nutrients for plant growth. A soil test will reveal whether your soil is deficient in one or more of the “big three” nutrients. In that scenario, when you prepare to plant your sweet potatoes, you should apply a supplement to offer the appropriate nutrients for your soil.