Food, Garden

How to plant sweet potatoes: complete guide

How to plant sweet potatoes

Outlines how to plant sweet potatoes, soil conditions, why not to bother with seed, how to grow roots from cut sweet potatoes and what to watch out for. The methods for how to grow sweet potatoes are very simple and almost foolproof, if you just take note of what to avoid.

The origin of sweet potatoes

Like water spinach (Ipomoea aquatica), sweet potatoes (Ipomoea batatas) belong to the Convolvulaceae family. The sweet potatoes originally come from Central America, but in the 15th century they came to Europe and the rest of the world through the Spanish.

Because of their tasty and nutrient-rich tubers, they have achieved great economic importance in large parts of the world. Especially in the poorer regions of South America and Africa, where the population depends on growing their own vegetables, sweet potatoes, also known as potatoes, are therefore one of the staple foods. Their name often causes confusion, however, because the sweet potato is actually only very distantly related to the well-known potato (Solanum tuberosum). With other tuberous plants such as the Jerusalem artichoke (Helianthus tuberosus), however, there is absolutely no relationship.

Appearance

The shape of the sweet potatoes, which are actually storage roots, varies from round to spindle-shaped. They grow up to 30 centimeters long and can even weigh several kilograms in their tropical home. The color of the tubers can be white, yellow, orange, pink or purple, depending on the variety. Long shoots with lots of foliage sprout from the tubers. The light to dark green leaves are heart-shaped and petiolate – at first glance they are reminiscent of ivy. The ornamental varieties that exist also develop pretty colorful flowers, but have a very short flowering period.

Where to grow sweet potatoes: Location and soil

The annual and not hardy sweet potatoes are heavy eaters and prefer a loose and sandy soil rich in nutrients and humus. A high nitrogen content is ideal. Batatas are very sensitive to cold, which is why they need a sunny and sheltered location in the garden. In our latitudes, they are therefore best grown in a balcony box, in a raised bed or in a greenhouse. In mild regions, however, they also thrive outside. If the soil moisture is even, the sweet potato sets up plenty of baby tubers during the summer months.

How to plant sweet potatoes: Preculture and planting

In contrast to potatoes, for example, sowing sweet potatoes is not really worthwhile, as the seeds germinate very poorly. The preculture of tubers works better. The planting time for potatoes usually begins at the end of winter dormancy in April and May, but the plants can be driven forward as early as January. To do this, the sweet potato tubers are simply placed in buckets or boxes with loose soil. In a bright room, the tubers sprout after a few weeks with uniform soil moisture.

How to grow sweet potatoes from slips

How to plant sweet potatoes

You can also hang the sweet potato slips or tubers halfway in a glass with water, similar to an avocado seed, and place them on a well-lit windowsill. If the shoots are sufficiently long – about 20 to 30 centimeters – you can either plant the whole tuber or just the shoot cuttings. If you use the whole tuber, it should be about halfway out of the soil.

If you don’t have a greenhouse, you should only have sweet potatoes after the frosts because of the risk of frostburnt outdoors. When no more frost is expected, the exotic species are given a sheltered place in large planters on the balcony or terrace, and in a mild wine-growing climate they also mature in the open-air bed. For a good harvest, planters with a capacity of at least 30 liters are required. If you plant the potatoes in the bed, a row distance of 30 to 50 centimeters must be maintained.

Crop rotation and mixed culture

In the case of heavily consuming root vegetables such as sweet potatoes, adherence to a crop rotation is absolutely recommended for successful cultivation. In this way you prevent diseases, pests and one-sided leaching of the soil at the same time. So change the bed year after year and preferably plant different summer flowers as neighbors. A mixed planting with carrots or broad beans is also possible.

How to plant sweet potatoes: Maintenance

Make sure that the plants are well protected from wind and cold rain. Regular watering is essential for longer periods of drought and for keeping in buckets.

How to plant sweet potatoes: Harvesting

The sweet potato harvest begins in September. As soon as the plants turn yellow in autumn, the tubers are ready for harvest. The warmth-loving Central American cannot stand the cold – the plants die at temperatures below ten degrees. A thick layer of mulch or a cover made of straw can delay the harvest a little longer. The harvested tubers should air dry for about two days before they are consumed. 

Attention: Sweet potatoes should dry briefly after harvesting and be processed quickly. Unlike potatoes, potatoes are only suitable for storage to a limited extent. Surplus sweet potatoes can be stored in a cool, dry room for a short time. If stored for too long, however, there is a risk that the tubers will rot.

Varieties to consider

The ‘Beauregard’ variety is to be recommended in terms of taste, has a reliable yield and is also very suitable for cultivation in our latitudes. The cultivation time is around 95 days. The variety ‘Orleans’ is very similar. ‘Bonita’ has white meat and a very smooth skin. The sweet potato variety ‘Murasaki’ has a striking dark red to purple skin and is reminiscent of sweet chestnuts in terms of taste. ‘Evangeline’ tastes particularly sweet and is therefore mainly used for exotic desserts. The sweet potato variety ‘Erato Orange’ has also proven itself in cultivation

Sweet potatoes can be prepared in a similar way to potatoes, so they can be baked, boiled or deep-fried. In terms of consistency, they are fibrous to floury and, due to their high sugar and starch content, have a delicately sweet taste. Batatas are extremely valuable for health. Because they contain a substance called caiapo, which can lower high blood sugar and cholesterol levels. The leaves of the sweet potatoes can be prepared like spinach .

Tip: Sweet potatoes are not just a tasty vegetable, some ornamental varieties also show attractive white or pink flowers in early summer. Unfortunately, they’re a bit short-lived. Varieties such as ‘Terrace Lime’ with light green, ‘Blacky’ with black-green and ‘Tricolor’ with green-pink-white pied foliage are therefore often used as potted or balcony plants. They also cut a fine figure as annual greening of pergolas and climbing frames.

Multiplication

The proliferation of sweet potatoes is easy. They are usually propagated by shoot cuttings. The cuttings are cut from the tuber for propagation, the lowest leaves are removed and about two thirds of their length is inserted into the earth at an angle.

Diseases and pests

Sweet potatoes are fairly resilient to plant diseases and pests. Only snails now and then attack the tubers. It is best to check the plants regularly for infestation and pick the snails off by hand as quickly as possible.

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