Kohlrabiis a biennial vegetable of the cabbage family, the edible part of which is a shortened, thickened stem.The nutritional values of kohlrabiand its interesting taste make it a good idea to include this vegetable in your diet. See whatcultivating kohlrabi in the garden looks likeand learn about the bestkohlrabi varietiesfor amateur cultivation. We also advise how toreproduce kohlrabifrom your own cultivation and what diseases and pests attack this vegetable.
Kohlrabi - Brassica oleracea var. gongyloides
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What does kohlrabi look like?
Kohlrabi(Brassica oleracea var. Gongyloides) is a purely cultivated species, it does not occur in natural stands. Its popularity is due to its nutritional, dietary and taste values. In the first year of cultivation, kohlrabi forms a strongly shortened, fleshy stem - a spherical or oval thickening, which is the edible part of the plant. In the second year, the plant forms an inflorescence shoot. Due to the anthocyaninsthe edible bulge of kohlrabican turn white, green, bluish-violet or purple in color, but this has no effect on its taste.
Kohlrabi - nutritional values
Kohlrabi is low in calories100 g of this vegetable is only 41.7 kcal. It is also a rich source of vitamins and minerals, such as: vitamins A, B1, B2, B3, B6, phosphorus, calcium, magnesium, selenium, cob alt, iron, sodium, and potassium.The vitamin C content of kohlrabiis so high that it is enough to eat one medium-sized kohlrabi to provide the daily dose of this vitamin that is needed by an adult.
Lutein, the source of which is kohlrabi , affects the proper functioning of the eyesight. The isothiocyanins and indoles in kohlrabi protect the body against the development of cancer. They also show fungicidal and bactericidal properties.
Kohlrabi is a valuable source of vitamins and minerals
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Not only the kohlrabi thickening, but also its leaves contain a lot of vitamin C, calcium and iron. They have a cleansing, anti-inflammatory effect and lower blood pressure.
The nutritional values of kohlrabimake it worth eating raw. It can be eaten as an ingredient in salads, as well as in casseroles, vegetable stews and even soups.
Kohlrabi - varieties
Kohlrabi varieties differ from each otherin the shape of the bulb and its color as well as the cultivation time - for early, mid-early and late harvesting. We present the most popularkohlrabi varieties recommended for growing in the garden .
Kohlrabi - early varieties:
Kohlrabi 'Lanro'- is a variety with light skin and delicate flesh. It tolerates frost well and is suitable for accelerated cultivation.
Kohlrabi 'Viennese White'- a variety with white skin, it forms small lumps with a delicate flavor.
Kohlrabi 'Viennese Violet'- differs from Viennese White in color, a slightly longer vegetation period and less prone to wood.
Kohlrabi 'Kref' F1- this is a delicate flesh variety, not prone to wood, and resistant to cracking.
Kohlrabi 'Gabi'- has a bulbous, yellow-green and juicy bulb. The variety shows high resistance to cracking and wood graining.
Colorful varieties of kohlrabi
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Kohlrabi - medium early varieties
Kohlrabi 'Delikates Weiser'- forms strong, large spherical or flattened beads weighing approx. 90-140 g and light in color. Creates medium-sized swells, recommended for both early and post-crop cultivation, the growing period lasts 55 days.
Kohlrabi 'Konmar' F1- is a variety with white, delicate flesh and high resistance to leaf diseases. It shows a low susceptibility of the bead to cracking.
Kohlrabi 'Komet' F1- is a variety with a tender and juicy flesh. It is characterized by excellent fertility and high resistance to wood.
Kohlrabi 'Troy' F1- intended to be eaten raw, stored for several months and frozen. White-green, spherical flattened thickenings weigh up to 6 kg.
Kohlrabi - late varieties
Kohlrabi 'Alka'- with dark purple and juicy thickening, intended for direct consumption and long storage. The vegetation period is 85 days.
Kohlrabi Delikatess Blauer- this is a fertile variety with blue-purple, slightly large and spherical swells.
Blue Butter Kohlrabi- has a growing season of up to 75 days. This variety forms large dark red lumps with white flesh that does not tend to be woody.
Giant kohlrabi- forms large thickenings up to 4 kg in weight and does not tend to stick to wood.
Kohlrabi - cultivation
Kohlrabi grows best in a sunny positionat a temperature of 12-18 ° C. It tolerates temperature drops well. Only young plants should be especially taken care of, as long-term cold weather causes the inflorescence shoots to be knocked out.The soil for growing kohlrabi should be rich , humus, fertile, pH 6.0-6.5.
Kohlrabi has a shallow root system, therefore it requires moist soils.Insufficient amount of water causes the lumps to become woody. Excess water causes them to break. That is whyan important care treatment in kohlrabi cultivation is regular irrigationduring the period of bulking.
Excess water leads to kohlrabi cracking
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It is recommended to grow kohlrabiin the second or third year after manure. Kohlrabi mineral fertilization should be carried out on the basis of the results of soil analysis. The plant is sensitive to chlorine, so potassium fertilizers should be used in the form of sulphates.The best form of nitrogen fertilization for kohlrabiis ammonium nitrate or calcium ammonium nitrate.
Kohlrabi should not grow in the same place more often than every 4 yearsProper crop rotation of vegetables will protect the plant against many diseases that may survive in the soil. Also, due to diseases,kohlrabi is not grown after other cruciferous vegetables , such as: broccoli, kale, cauliflower, head cabbage, Chinese cabbage, kale.
Kohlrabi - reproduction
Kohlrabi is propagated from seeds.Sowing dates for kohlrabi seedsare as follows:
- for early harvestsow it under cover in the second half of February, and plant it permanently in mid-April,
- for summer harvestkohlrabi seeds are sown in early April, and seedlings are planted in May and June,
- kohlrabi varieties intendedfor autumn harvestsown in June and planted permanently in August.
Kohlrabi seedlings planted into the ground
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Kohlrabi seeds can be sown in boxes , and when the seedling is about 2 weeks old, pluck the seedlings into separate pots with a diameter of 10-12 cm. In small-scale cultivation, seeds can also be sown in pots straight away. We put2-3 kohlrabi seeds in each potand leave only the strongest seedling after emergence.
Kohlrabi seeds need temperatures around 14-20 ° Cfor emergence. After germination, we lower the temperature to 12 ° C. Before planting in a permanent place, harden the seedlings by gradually lowering the temperature and limiting watering so that the plants get better.
After about two months of productionthe kohlrabi seedling with 4-5 leaves can be planted permanentlyDepending on the variety, the plants are planted 40x50, 40x30 or 30x15 cm apart. The use of agrotextile covers or foil in the cultivation of early harvest will significantly accelerate the growth of plants and reduce their knocking out into shoots.
Ripe kohlrabi ready for harvest
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Kohlrabi - diseases and pests
Chemical protection of kohlrabi against diseasesis difficult due to the short growing season of this vegetable and the small amount of registered plant protection products.The possibly available preparations, permitted for use in amateur crops, are registered mainly for the protection of cabbage, not kohlrabi. That is why it is worth taking a closer look at natural means and methods of plant protection, especially ifwe grow kohlrabi as an amateurin our own garden.
Kohlrabi fungal diseasesit is worth combating with the help of natural extracts of herbs and weeds such as: nettle, horsetail or yarrow. Plant slurry can also help fight disease and pests by strengthening plants and making them more resistant.
First of all, however, we shouldremove crop residues from the beds , because pathogens can winter there until the next year. We must also takeat least 4-year breaks in the cultivation of kohlrabiand other cruciferous vegetables in a given position.
Downy mildew of brassica- is a fungal disease, the symptoms of which are brown spots on the upper side of the leaf and white or gray mycelium on the underside.Dampness favors the disease. In order toprotect kohlrabi from mildew , it is worth spraying with horsetail decoction and nettle slurry. In both cases, plants and soil should be sprayed several times every 2-3 weeks. If we are not able to prepare the above-mentioned preparations ourselves, you can buy a ready-made preparation of field horsetail called Evasiol and a ready-made Target Natural nettle extract in a garden shop.
Black cruciferous- this disease, also called alternariosis, manifests itself with oblong brown spots on the seedling stems, and on older plants - round, necrotic spots on the outer leaves. The pathogen hibernates in plant debris left behind after harvesting. The source of infection can also be weeds from the cabbage family and infected kohlrabi seeds.Kohlrabi can be protected against this disease by spraying with Signum 33 WG. The agent can be applied from the 3 leaf phase to the end of the phase, when the bead reaches 70% of its typical size.The first treatment is performed preventively, according to the signaling, or at the first symptoms of the disease. The recommended dose of the preparation is 10 g per 6-8 liters of water, which is enough for 100 m² of beds. Signum 33 WG can be applied up to 3 times during the growing season, at intervals of 3-4 weeks.
White rust cruciferous- is a fungal disease, the symptoms of which are visible on leaves, shoots and inflorescences. Necrotic spots appear, within which vesicles form. By bursting, they release the spores of the fungus. Affected organs deform and die.
Earthen fleas- these are small beetles biting holes in leaves. They can destroy the entire kohlrabi crop. The most effective way to combat these pests is to cover the plants with agrotextile or a dense mesh. Sticky tablets covered with a substance to which beetles stick to it can also be used. Some plants such as catnip, lettuce and spinach deter fleas by reducing their occurrence.A home method of treating ground fleas is also dusting plants with bas alt flour.
Bielinek kapustnik- damage is caused by caterpillars of this butterfly feeding on kohlrabi. Symptoms of feeding the caterpillars of cabbage moth in the form of bitten holes may resemble damage caused by fleas or caterpillars of the cruciferous moth.
In order to avoid the invasion of cabbage miteplant next to kohlrabi, plants whose smell scares or confuses butterfliesTo repel cabbage moth, you can use plants with a strong smell, such as: hyssop, sage, thyme, lavender, marjoram, mint, marigold. The most popular, however, is planting cruciferous vegetables with tomatoes and celery.
For the spraying of cabbage soup , it is recommended to use the biological preparation Lepinox Plus. You can also use herbs and weeds such as yarrow or tansy for self-preparation of natural preparations to fight white moth.
Cabbage aphid- feeds on kohlrabi leaves and feeds on plant sap. Affected leaves deform, discolor, then wilt and die.
A natural way to fight aphids is to spray with potassium soap or baking soda. You can also use a spray with a preparation of onion, garlic, nettle, yarrow, mugwort, wormwood or dandelion. To prevent the aphids from settling on the plants, they can also be sprinkled with bas alt flour or sprayed with the natural preparation Emulpar 940 EC.
Snails feeding on kohlrabi leaves and bulgescause damage, disease and plant dieback. Against these kohlrabi pests, we can use a snail trap with a decoy agent and the ecological snail pellet Ferramol GR Target Natural. The use of snail traps and organic granules is completely safe in the cultivation of vegetables.It is also helpful to dust the soil and plants with bas alt flour, which sticks to the bodies of snails and makes it difficult for them to move.
MSc Eng. Anna Błaszczak
