Growing Organic Sweet Potatoes – Planting, Farming, Tips, Ideas

Introduction to Growing Organic Sweet Potatoes

Sweet Potato is an herbaceous perennial crop in the family Convolvulaceae. The botanical name of Sweet Potato is Ipomoea batatas and this crop is mainly grown because of its sweet taste and starchy roots. The tubers are a rich source of beta-carotene and used as anti-oxidants. The Sweet Potato plant is a branching, creeping vine with spirally arranged lobed, heart-shaped plant leaves and white or lavender flowers. This plant has enlarged roots called tubers which act as an energy store for the plant. In this article we also covered the below topics about Sweet Potatoes;

  • How many Sweet Potatoes can one plant produce
  • How do you increase the yield of a Sweet Potato
  • Do Sweet Potatoes need to be organic
  • How do you grow organic Sweet Potatoes
  • How do you propagate Sweet Potatoes
  • How much space does a Sweet Potato need
  • How do you cut Sweet Potato slips for the process of planting

A Step by Step Guide to Growing Organic Sweet Potatoes

In India, Sweet Potato is called ‘Sakharkanda’. Sweet Potatoes produce lush foliage and Sweet tubers. The Sweet Potatoes have low nutrient levels and you can fertilize them successfully with organic materials or with a low-nitrogen organic fertilizer blend.  About 2 lakh of land is under cultivation of Sweet Potatoes in India. Bihar, West Bengal, Uttar Pradesh, and Orissa are the major Sweet Potato growing states in India.

Guide to Growing Organic Sweet Potatoes
Guide to Growing Organic Sweet Potatoes (Image credit: Pixabay)

Different Cultivars/Varieties of Sweet Potatoes

Variation among the cultivar exists in respect of skin color, shape, and size of tubers. Mostly local varieties are grown. There are some Sweet Potato varieties like H- 268, Pusa Safed, Pusa red, Pusa sunahari, NO-4004, S-30, Klamath, and the recent one Skarkand – 5. The period of maturity ranges from 90 to 140 days.

Some Organic Sweet Potato Varieties are Jewel Yams, Garnet Yams, Covington Sweets, Japanese Sweets (aka Oriental Sweets), Hannah Sweets, and Stokes Purple Sweets.

Soil Requirement for Growing Organic Sweet Potatoes

Sweet Potato is grown in a variety of soil types ranging from sandy to loamy soil, but it gives the best result when grown under sandy loam soil having high fertility and a good drainage system. Sweet Potato cultivation should be avoided in light sandy and heavy clayey soil as it is not good for tuber development. It requires a pH level ranging from 5.8-6.0 is best for Sweet Potato cultivation.

Sweet Potatoes require loose, well-drained soil to form large tubers. You don’t want the plant roots to face resistance when they try to expand within the soil. The optimal pH level range for maximum yields of high-quality Sweet Potatoes is 5.8 to 6.0. If using lime to raise the pH level, apply dolomitic lime because it also contains magnesium.

Land Preparation for Growing Organic Sweet Potatoes

First, prepare land well in advance of planting time. Before setting out Sweet Potato slips turn the soil for several weeks. Then, to allow beds to settle and become firm, make final bed preparation several days before setting. Beds must be at least 8 inches high and as broad as row widths will permit. Narrow beds dry out quickly and restrict root growth. Soil infested with root-knot nematodes must be treated with a nematicide before transplanting.

Generally, Sweet Potatoes need full sun and well-drained soil. These plants are not heavy feeders but do require a good balance of nitrogen, potassium, and phosphorous. Work in a slow-release organic fertilizer before planting and too much nitrogen produces leafy growth at the expense of the roots. One Sweet Potato will produce between 3 and 5 slips.

Requirements for Growing Organic Sweet Potatoes

  • Sweet Potato plants grow well in tropical and subtropical climates.
  • They grow best at temperatures over 25°C in well-draining, loamy soil with a pH level of 5.6–6.6.
  • Sweet Potatoes must be planted in full sun and require plenty of space as the vines will spread over large areas. ”Slips” Sweet Potatoes are grown from plants known as slips. These slips are plants that have been grown from a mature Sweet Potato tuber.
  • Usually, slips can be purchased or grown at home. The easiest method to grow slips is to place a Sweet Potato in a water jar using toothpicks to support it. Then, place it in a bright, sunny window, and allow it to sprout. Some of the sprouts will develop roots, others may not develop roots.
  • The shoots that have roots can be snapped from the main tuber and then planted in individual pots. Those without must be snapped off and placed in a jar of water until they begin to develop roots.

Sowing Time and Method for Growing Organic Sweet Potatoes

For optimum yield, tubers must be sown in nursery beds from January to February and the optimum time for planting vines in the field is from April to July. Use depth of 20 to 25 cm for tuber planting.

Mainly propagation is done by using tubers or vine cuttings. In the vine cutting method, the tubers are taken from the old vines and then planted on prepared nursery beds. Generally, vines are planted in ridges or on prepared flatbeds. The host plant has at least 4 nodes. Row spacing of about 60 cm and within row spacing of 30 cm is used.

Spacing and Seed Rate for Growing Organic Sweet Potatoes

Use row to row spacing of about 60 cm and plant to plant spacing of 30 cm. Use 25,000 to 30,000 vines cutting in per acre land. Vines are then planted in the main fields in a 1-acre land.

When and Where You Should Grow Sweet Potatoes

Before planting Sweet Potatoes, as with most crops, you’ll want to prepare your soil. Thankfully, Sweet Potatoes are not picky. The plants prefer loamy soil which is well-drained and not overly rich. We advise you to mix in a 1-inch layer of compost and break up any clumps. Then, thoroughly dampen the bed with fresh water. This is the proper time to check the soil’s acidity. You are aiming for a pH level between 5.8 and 6.0. Sweet Potatoes can tolerate a more acidic soil (towards 5.0) if necessary and amend your soil as needed until you achieve the proper balance.

Sweet Potato plants prefer more sandy soil, as opposed to heavier clay. If you are in an area with heavy clay and consider utilizing a raised bed. The benefit of planting your Sweet Potato crops in a raised bed is that you can build your soil to the specifications required for your crop. For Sweet Potatoes, you’ll want to amend the soil with compost and sand. Potatoes planted in heavy clay will grow to be thinner and then misshapen. Proper Sweet Potato root development is dependent upon adequate airspace throughout the soil and good aeration.

If you are located in a warmer climate zone, you may wish to plant Sweet Potatoes around a month after the last spring frost. Sweet Potato plants prefer hotter ground and air temperatures. You will want to wait until you can depend upon consistently warm temperatures in both. It may be a good suggestion to cover the soil with black plastic or black fabric mulch about 3 weeks before planting. This will help trap the heat from the sun and then speed up the warming of the soil.

Step by Step Process for Growing Organic Sweet Potatoes

Step 1) Sweet Potato plants grow best on medium to light well-drained sandy soils. While this crop can be grown in heavier soils, roots can be rough-skinned and irregular as a result. Fields high in organic matter must be avoided.

Step 2) Sweet Potatoes should not be grown on the same land more than once every 3 years. And, avoid fields with a history of difficult to control perennial weeds. Also, avoid locations that have had corn within the last 5 years to reduce the potential for wireworm damage.

Step 3) Sweet Potato propagation is from vine cuttings commonly referred to as “slips.” While certified disease-free slips can be purchased, it is more economical for growers to propagate their stock, if they have their Sweet Potatoes to use for starting slips. 10 to 12 bushels of disease-free Sweet Potatoes must be bedded to produce enough slips for 1 acre. Normally, 16 to 20 square feet of bed surface will be needed for each bushel. Sweet Potatoes are bedded about seven weeks before field-setting time.

Step 4) Sweet Potatoes require full sun and at least 100 warm days and nights to produce decent tubers. The soil must be moist and well-drained.

Step 5) Hilling the soil helps to keep the tubers warm and also improves drainage. Laying dark plastic mulch over the top of the mounds, with the vines poking through, and will help colder region gardeners raise the soil’s temperature. Top growth might be slow to start, but once they get rooted in and the daytime temperature levels heat up, their growth will become vigorous.

Step 6) Once the vines begin to develop, make sure to cultivate underneath, to prevent the vines from rooting in and which will only create competition for the main set of roots. Otherwise, Sweet Potatoes are self-reliant and require very little effort until harvest. Fertilize with compost or manure tea, only if necessary, about 6 weeks after planting.

Water Requirement for Growing Organic Sweet Potatoes

Sweet Potato plants do well with ¾ to 1 inch of rain per week.  Without enough water, the Potato development will be stunted and you’ll end up with some puny tubers. Also, they may be slightly deformed and not as sweet or tender.

It is a good idea to water in the early morning hours. Then, this gives the afternoon sun a chance to evaporate any unused water off the foliage. Wet foliage is a breeding ground for fungal and also bacterial infections. The drier the Sweet Potato vines stay and the better.  A long soak once a week, if there’s no rain, must be plenty. Avoid several shallow watering and the water just doesn’t get deep enough to where the roots can absorb it efficiently. If the soil is dry, go ahead and water the plants. If it’s soggy, hold off and let the ground dry out a bit. It’s not necessary to mulch around Sweet Potato plants as the vines spread out and keeping the weeds down and keeping the soil moist.

Stop watering plants altogether a couple of weeks before they are to be harvested. Generally, when the vines begin to turn yellow, it’s a sign to stop watering. Then, this will allow the Sweet Potatoes time to fully mature and concentrate their sugars.

Fertilizers for Growing Organic Sweet Potatoes

Bone meal, kelp meal, and green sand are organic choices for growing Sweet Potatoes that are lower in nitrogen than potassium and phosphorus. Don’t over-fertilize the plant. Sweet Potatoes are not heavy feeders.

Sweet Potato plants prefer to grow in soil that is high in potassium. Instead of using synthetic fertilizer use compost, manure, or one of the below additives.

Greensand – the main component of Greensand is gluconate, which is a mineral derived from ocean sediment, high in potassium, iron, magnesium, and aluminium. It is green in color due to this mineral. Then, this organic fertilizer slowly releases nutrients over time in the soil. 

Kelp Meal – It is valued for its micro and macro-nutrients – nitrogen, potassium, and phosphorus make it an ideal organic fertilizer for fruit and vegetable gardens. Comprised of seaweed, harvested from our nutrient-rich oceans, provides healthier plant growth, stronger yields, and overall enhances the garden. Kelp meal comes in three different forms – liquid, powder, or concentrates for those gardens with low levels of nutrients.

Organic Fertilizer Blends – Use a commercial organic fertilizer for the initial application or side dressing. Also, organic fertilizers provide a more exact nutrient ratio compared to compost, making them suitable in nutrient-depleted soils. Choose a low-nitrogen organic mix. For example, a 5-10-10 blend contains 5% nitrogen and 10% each of phosphorus and potassium. Nutrients may be supplied with feather meal, molasses, or potash. Use 4 pounds of organic fertilizer blends for every 100 feet of Sweet Potato row before planting. Then, check the package rates because they vary widely.

Midseason Side Dressing – A side dressing of compost or leaf mold in midsummer, about 6 to 8 weeks after the Sweet Potato plants begin growing, provides a new infusion of nutrients to fuel growth. Dig shallow, 2-inch furrows 6 inches away from the plants, taking care not to damage any developing tubers, and then spread the compost in the furrow. Otherwise, spread a 1-inch layer of compost over the soil surrounding the plants, but don’t place the compost directly against plant stems. And, nutrients will leach into the soil from the compost for the remainder of the growing season. If you use an organic fertilizer blend instead of compost, apply 2 pounds per 100-foot row, or according to label rates, applying it using the furrow method.

Irrigation Requirement for Growing Organic Sweet Potatoes

Sweet Potato plant needs less irrigation the most critical stage of moisture supply is about 40 days after planting. Excessive moisture supply deteriorates the quality of Potato tubers.

Problems in Growing Organic Sweet Potatoes

  • Sweet Potato plants are rarely bothered by pests or diseases. The main insect pests are those that feed on the roots like wireworms, flea beetle larvae, and Sweet Potato weevils. Plant diseases include black rot and scurf, Fusarium wilt, root-knot nematodes, and post-harvest rots. Resistant cultivars, crop rotations, sanitation, and weed management are important tools in disease and insect management in Sweet Potato plants. Pesticide applications can be necessary for some seasons.
  • The Sweet Potato weevil disease is a one-quarter-inch long insect with a dark blue head and wings and a reddish-orange body. It will puncture stems and plant roots to lay its eggs inside. Then, the larvae will then feed on the flesh of the plant. Adult weevils attack vines and leaves. Also, weevils spread rot, which can be identified by growing brown or black areas on stems near the soil and at the ends of the stem. The best method to prevent this problem is to use certified disease-resistant slips and practice four-year crop rotation.
  • Black rot can be identified by the presence of circular-shaped, dark-colored depressions on plant roots. To treat, discard infected Sweet Potatoes and then carefully cure undamaged roots of the same crop. Be aware, black rot looks similar to the much-less-serious “Scurf.”
  • Scurf disease shows up as round darkened spots on root surfaces, but these spots are small and do not affect the edible quality of the crop.
  • Stem rot is also known as wilt. It is a type of fungus which enters through an injury to the plant. Stem rot may not kill your plant, but it will drastically reduce the harvest. To minimize Sweet Potatoes’ susceptibility to this type of fungus, again plant only certified and healthy slips.

When and How to Harvest Sweet Potatoes

In case if you miss this: Vegetable Farming Tips In India.

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Harvested Sweet Potatoes (Pic source: Pixabay)

The time of harvesting Sweet Potatoes depends on the variety. Before harvest vines are cut and tubers are dug with the help of a fork.

Sweet Potatoes are ready to harvest just as the ends of the vines turn to yellow color.  Judge the maturity by cutting tuber. If latex dried up without turning black color, it is sure that the Sweet Potato is matured. Irrigate the crop 4 to 6 days before harvest to facilitate harvesting. Take care that tubers are not injured while the time of harvesting.


  1. If bindweed and flea beetles are common to my garden is it possible to grow sweet potatoes in the southern tier of upstate New York?


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