Sweet Potato: Tips on Cultivation, Harvest & Storage

Sweet potatoes are one of the healthiest vegetables, they are delicious and versatile in the kitchen. We give tips on growing, harvesting and storing.

Can you actually imagine a food truck festival or other culinary events without sweet potatoes? The sweet potato is now an integral part of every supermarket and also part of many menus. The sweet potato (Ipomea batata) originally comes from the tropical and subtropical regions of South America, where it was given the name Batate by the indigenous people. To this day, the exact origin is not known. In 16. Century before the potato reached England, sweet potatoes were already being traded in Europe. At this time, the sweet potato was also given the name "potato", which was later used for the potato we know. Incidentally, the relationship between the potato and the sweet potato is not particularly great either. A very close relative of the sweet potato, for example, is the morning glory (syn.: morning glory), which is very well known in this country. In principle, a sweet potato is just a morning glory with the ability to form a tuber. And this root tuber has it all. For example, the healthy vegetable contains twice as much vitamin C as a potato and at the same time the tuber is a very rich source of energy.

Growing sweet potatoes: This is how it works in your own garden

Although the sweet potato is a very heat-loving plant, cultivation can also work very well in our latitudes. Since the demand for sweet potatoes continues to grow, attempts are even being made to cultivate the sweet potato on a large scale in Germany. So that you too can really harvest your own sweet potatoes at the end of the gardening season, we have summarized all the important information about care, location and propagation for you:

propagation

The sweet potato is usually not propagated by seeds. It is much easier to root the tuber or use cuttings with or without roots. However, you should not necessarily take the tubers from the supermarket if you are looking for a yield. The varieties used are poorly adapted to our rather cold weather. It is better to buy rooted young plants of proven varieties. As soon as the small plants have arrived at your place, they should be given a larger pot. The young plants are then grown on the warmest and sunniest windowsill until the temperatures in the garden no longer fall below 10 °C. Because not only frost is absolutely deadly for the sweet potato, the morning glory plant is also damaged at single-digit temperatures.

tip: You can continue to take cuttings from the plants on the windowsill and save quite a bit of money. It is best to place the cut cuttings in moist potting soil and continue cultivating them in a mini greenhouse at a temperature of at least 20 °C. After 2 or 3 weeks at the latest the first roots should form.

location

As soon as the ice saints are over and the thermometer does not fall below 10 °C at night, plant the sweet potato plants that you have preferred outdoors. Full sun locations are preferred. Since the perennial loves temperatures around 28 °C, a heat-storing south wall or the greenhouse is the best location. In the greenhouse, for example, a mixed culture with tomatoes or cucumbers would be conceivable. The sweet potato grows creeping and can therefore act as a ground cover and also keeps annoying weeds away. But also the culture in the vegetable bed or in the pot brings good yields.

If you choose a pot culture, the pot should hold at least 20 liters and be filled with a nutrient-rich and well-drained substrate. Well suited is our nutrient-rich and peat-free Organic tomato & vegetable soil. The soil should also be as permeable as possible in the bed or raised bed, because the sweet potato does not tolerate waterlogging. Therefore, a loamy-sandy soil is ideal.

By the way, there is a trick with which the batata feels even more comfortable: For this, 60 cm wide and 20 cm high mounds of earth must be created in the vegetable patch. If several dams are created, they should be at least one meter apart. The small plants can then be planted on the ridges at a distance of at least 30 cm. Growing on the dams offers two key advantages. First, the mounds of earth heat up faster than a regular vegetable patch. The tubers are always a little warmer and can grow faster. And in addition, the rainwater can flow off faster thanks to the dam construction and the risk of waterlogging is reduced. When growing in a pot, you can achieve a higher soil temperature with a dark plastic pot.

pro tip: In order for a nice and even root bulb to form, the root ball must be carefully loosened before transplanting.

watering and fertilizing

The water requirements of the sweet potato are relatively high. The soil should always be moist and never dry out deep into the soil. Therefore, it must always be poured as soon as the top layer of soil has dried out; it is better to water young plants beforehand. In the summer months, the plants form a lot of leaf mass and thus also lose large amounts of water. For this reason, we recommend watering extensively, especially during warm, dry periods. The sweet potato can withstand shorter periods of drought, but the quality and yield of the tubers suffer as a result. At the end of the season (September - October) the watering should be reduced. The soil must then be kept drier overall, as the risk of rot increases.

The nutrient requirement of the sweet potato is medium. For the bed culture we therefore recommend fertilizing with 3 liters of mature compost and 100 g horn meal per m². A good alternative is a high-quality vegetable fertilizer such as our Plantura Organic Tomato Fertilizer with a long-term effect. However, if the sweet potatoes are grown in pots, they must be fertilized regularly. To do this, wait until the sweet potato begins strong leaf growth. Then every week it is fertilized with liquid fertilizer. Our Plantura is recommended here Organic Tomato & Vegetable Fertilizer, an organic liquid fertilizer that contains all the important nutrients and strengthens the roots.

care tips

If the sweet potato has a good location, is watered regularly and is well supplied with nutrients, then it will grow by itself. Special care is not necessary. Also, do not despair if the plants grow very slowly at first. That's perfectly normal. Eventually there comes a point where the plants form one leaf at a time. The initially empty bed is then a green carpet in a few weeks and at this point it quickly becomes clear why the small plants have to be planted so far apart.

You can find even more information in our article on the subject grow sweet potato.

Sweet Potato: New, tried and tested and robust varieties

There is an almost incalculable number of varieties of sweet potatoes. Most of the varieties differ in tuber color and shape. For example, there are breeds with red, yellow or white skin, with orange, white or purple flesh. Some varieties are also suitable as ornamental plants due to their special leaf colors. In addition, other properties are also important, especially for our climate: These include, above all, the shortest possible cultivation time and tolerance to cool weather.

Because sweet potatoes in this country do not flower under normal conditions and many varieties cannot form germinable seeds, seeds are hardly available commercially. Therefore, mostly only plants can be purchased. The selection of varieties could also be larger in Germany. Due to the intense interest in the sweet potato, we are certain that the range of varieties will grow from year to year (even if the selection is still limited today). The varieties presented here have already been tested and are suitable for cultivation in Germany.

• Beauregard: Widespread variety with a short cultivation period (90-95 days). The tuber has a red colored skin and the flesh is orange. Very productive in Germany.
• Bonita: The variety is a real all-rounder in the kitchen. The skin is pink in color and the flesh is white-yellowish.
• Evangelina: Also suitable as an ornamental plant due to the wine-red shoot tips. The tuber color is red-purple and the flesh is orange. Due to the high sugar content, the variety is particularly suitable for desserts. Culture duration: 100 – 110 days.
• murasaki: A white-fleshed variety with a pink skin. The Japanese breed is said to have a sweet and nutty taste and is particularly suitable for chips. The culture lasts relatively long at 120-130 days.
• Oklamex Red: Unfortunately, this variety is not yet available in Germany. The tubers have a dark red skin and salmon-colored flesh. The special thing about this variety is the high sugar content.
• Sumor: The Sumor variety was bred for a high vitamin C content. But the variety also has a lot to offer in terms of colour, because the flesh has a very nice white to yellow colour. Unfortunately, this variety is not yet available in Germany.
• Black Hearth: For the Black Hearth variety, the focus was on the leaves. It is therefore more of an ornamental plant. The leaves have an intense violet color and should not be missing in any flower box.

Sweet potatoes: harvest, storage and preservation

The sweet potato only begins to form tubers in September. Harvest time is around October, although the date may change depending on the weather. Since the tuber does not tolerate frost, it must always be harvested before the first frost. You can tell the best time to harvest by the color of the leaves. When the leaves turn yellow, the tubers contain most of the ingredients. But even if you do not reach the optimal harvest time, the sweet potatoes you have harvested yourself are delicious and tasty. Unfortunately, since the sun does not shine as intensely here as it does in the home areas of the Batata, you must expect a little less sweetness. However, by choosing the right variety, you can avoid the problem.

You should exercise caution when harvesting the annual plant. The tubers must not be injured, otherwise rot will quickly occur during storage. By the way, the sweet potato tuber is a real root tuber. With the normal potato, on the other hand, it is a tuber that is harvested. Sweet potatoes can be used immediately after harvest or the tubers are stored. When storing, however, there are a few points to consider so that taste and firmness are preserved and At the same time, no rot occurs: Only undamaged and clean root bulbs may be stored will. Tubers that were injured during harvest should be eaten immediately. Storage should take place at temperatures between 12 and 16 °C. If the temperatures are too low, cold damage occurs and at higher temperatures the storage time, which is 3 to 4 weeks under optimal conditions, is reduced. The humidity should also be as high as possible during storage.

So that the sweet potatoes can be stored for longer and also contain more sugar, so-called "curing" is carried out. The process converts starch into sugar and the tubers can be kept for up to 12 months. However, this long storage time can only be achieved if the curing is carried out in special air-conditioned rooms. The sweet potatoes are stored in these rooms for 4 to 10 days at around 30 °C and 80 – 95 % humidity. However, most households will not have the resources to cure under these exact conditions. But there is also a simpler method: the harvested sweet potatoes are wrapped in black foil for 5 days and placed in the sun during the day (and in the warmest room at night). This does not result in perfect curing, but the sweet potatoes have a few weeks longer shelf life and also contain more sugar.

tip: You shouldn't freeze raw yams.

Diseases and Pests of Sweet Potatoes

The sweet potato does not seem to be a very popular plant for our pests. In the cultivation attempts that were made in this country, little or no damage occurred. Only at the end of the season is there a risk of mice attacking the high-energy tubers. If you also have problems with mice, an early harvest usually helps. In addition, weeds should be chopped regularly at the beginning. Later, when the ground is covered by the creeping leaf shoots of the sweet potato, weeds can usually no longer grow.

Ingredients and use in the kitchen

After the harvest, the question naturally arises as to how best to prepare the sweet potatoes. In any case, the vegetables should appear more often in your diet, because they are extremely healthy! First and foremost, the sweet potato is a healthy carbohydrate supplier with around 20 g of starch and 5 g of sugar per 100 g. This results in a calorific value of approx. 100 kcal for 100 g of sweet potatoes. The normal potato cannot quite keep up with the calories. In contrast to the potato, yellow-fleshed sweet potatoes also contain a lot of beta-carotene. Furthermore, the content of vitamin B2, vitamin A, vitamin C and iron should be emphasized. Overall, the sweet potato is a very nutritious and healthy vegetable.

Here you can find more about the components of the sweet potato.

Actually, all methods are suitable for the preparation. The sweet potato can be boiled, baked and fried. In Latin America and India, even an alcoholic drink called "Mobby" or "Marmoda" is made from the sweet potato. There are no limits to creativity when preparing sweet potatoes. Because of their sweet taste, sweet potatoes are particularly popular with small children. A puree or mash made from sweet potatoes is quick to make and very healthy at the same time. The fried version is particularly tasty. French fries or chips made from sweet potatoes taste at least as good as those made from normal potatoes. If you like it a little more exotic, you can use the sweet potato in a curry. No matter which preparation method you choose, sweet potatoes go well with pretty much any other vegetable or meat. With the slightly sweet note, countless dishes can be reinterpreted.

Tip for cooking: The sweet potato (just like regular potatoes) should always be cooked with its skin on. As a result, the valuable ingredients do not get into the cooking water.