Kale (lat. Brassica oleracea var. sabbauda) is a biennial plant from the cabbage family (Brassicaceae). It is grown for its edible leaves, which are blistered and branched.
Kale cultivation is common in our coastal areas where there is no frost, so it can easily be grown even in winter. If we compare it with cabbage, kale tolerates frost and low temperatures much better, so it is also grown in continental areas.
Kale leaves are blistered and do not lie firmly next to each other, so the head is much softer than cabbage. Its leaves are several shades of green, from dark green on the outside to yellow green on the inside of the head.
Kale cultivars that are grown as ornamental plants due to their decorative appearance can often be found.
Information
Latin: Brassica oleracea var. sabbauda
English: Kale
Family: Cabbage (Brassicaceae)
Height: up to 40 cm
Conditions: quality and humus soil
Climate: moderately warm and humid
Planting: February (seeds), April (seedlings)
Harvest: after temperatures drop below 0°C
Use: food
Relatives
Sowing
In order to get an early spring production of kale, the seeds are sown in warm beds, greenhouses or greenhouses in November and December, and after about 30 days they are planted. Kale can be easily sown throughout the year, which depends on the variety and the length of the growing season.
Early varieties of kale are planted at a distance of 40 x 40 cm or 50 x 50 cm, while large varieties are planted at larger distances, i.e. at 60 x 40 cm and 65 x 50 cm.
Tillage depends on the time of year when kale will be grown. Basic processing is done during autumn and winter, immediately after basic fertilization, and the plowing depth is 30 cm. The plowed furrow is left untouched until the spring months when the soil is prepared for planting seedlings.
For later planting, the whole process is done in one stage (fertilizing, plowing, discing, cultivating and leveling the soil), all with the aim of filling holes and removing depressions where water could be retained for longer.
Kale will do best if done after harvesting beans, green beans, peas, lentils, chickpeas and potatoes. It can be planted on the same area only after 4 years, all with the aim of avoiding diseases and pests and increasing the quality of the plantations.
Ground
If you want to grow kale, you will need to meet its humus and quality soil requirements. It can thrive on all types of soil, but on the condition that they are structural and deep and have a good capacity for air and water. Kale likes slightly acidic soils with a pH value of 6 to 6.5.
Lighter soils that heat up faster are recommended for spring planting of kale. In good climate and soil conditions and by choosing the right hybrid cultivars, early kale can be planted outdoors.
Fertilization
When preparing the soil for planting kale, you should add as much well-humified manure as possible. NPK fertilizer should be added to the basic fertilization in the ratio 12:11:18 + 3MgO.
Top dressing is done 10 days after transplanting. If it is about drip irrigation, top dressing is done twice a week, and with classic cultivation in the field, top dressing is done three times during cultivation.
The feeding process ends when the size of the heads is large enough to close the rows. In all cases, care should be taken to stop feeding 10 days before harvesting the kale.
Temperature
Kale seeds, with the necessary humidity, begin to germinate at a temperature of 1 to 5°C. At an optimal temperature of 20°C, the seeds germinate and the plant sprouts in 5 to 6 days.
For the vegetative growth of the plant, the best temperature is between 15 and 20°C, and the plant stops growing at temperatures higher than 25°C. When the conditions for the growth of kale are optimal again, growth continues.
In order to shape the heads of kale, the best temperature is 15 to 18°C.
Water
Young kale seedlings should be watered regularly. During the dry period, watering is necessary every evening. As the plant grows, watering is gradually reduced.
Plantation maintenance
When the seedlings are just sprouting and growing, it is necessary to water them regularly and remove weeds around them by weeding. When the plants grow, their lush green head protects the soil from weed formation, but if this does not happen, certain weed control agents can be used.
Protection against disease
In years when high air temperatures are recorded with the absence of precipitation, the development of pests on kale plantations is common.
Cabbage fever
It is common on cabbage plants, especially during dry and warm weather. It can damage the young plant the most. It is made with small beetles 1.5 to 3 mm long, which can be blue, dark green and black. Some species may also have a yellow line. Adult insects do the most damage by gnawing tiny holes in the leaves. They can overwinter in the soil, and in the spring months they come out and feed on cabbage plants. The females lay their eggs in the soil, and already in the summer, adult flea beetles can damage the kale.
Protection can be achieved by placing protective nets that prevent the entry of these pests, while chemical control of pests is carried out only when more than 10% of the leaves are damaged.
Cabbage bugs
Cabbage bugs cause damage by sucking the leaves, which is manifested by whitish dots. When it is a strong attack, they can cover the entire surface of the leaves. This disease is especially dangerous for young plants because it can destroy them.
Pests can overwinter under the remains of plants or even indoors, and in the spring months they develop their cycle again.
These are pests that are resistant to contact insecticides, so chemical methods are recommended.
Harmful caterpillars on cabbage plants
Harmful caterpillars (cabbage moth caterpillars, leafhopper caterpillars, cabbage whitefly caterpillars and others) usually do damage by biting the leaves which can lead to defoliation or failure to form kale heads. In addition to damage to the leaves, there is also damage caused by excrement, which leads to a reduced market value of kale.
Treatment is carried out with insecticides, depending on the type of caterpillar.
Tobacco thrips
Tobacco thrips are tiny insects of yellow or yellow-brown color, 1 to 1.2 mm in size. They cause damage by sucking the leaves, which leads to irregular nodules that are initially light in color but later darken. After that, saprophytic fungi appear on the attacked parts. The development of this pest is favored by high air temperatures and low relative humidity.
As prevention, it is recommended to regularly weed weeds and avoid planting kale near onions and leeks.
Cabbage aphid
The cabbage aphid is gray-green in color, and it causes damage by drying the leaves, which leads to curling and deformation, and ultimately drying of the leaves. They can overwinter as eggs on plants, and warm and dry weather favors them.
Cabbage shield moth
Cabbage shield moths are actually butterflies whose wings are coated with white waxy powder, while their body and head are slightly darker. They are about 1.5 mm long, and the larvae are small and look like earwigs. It causes damage by sucking the leaves and secreting honeydew, which also reduces the market value of the plant. The development of these pests is favored by high temperature and humidity.
Harvest
Kale is harvested exclusively by hand, by cutting off the heads after temperatures drop below 0°C. The longer kale is exposed to lower temperatures, the milder and sweeter its taste will be. This process only works in outdoor conditions, when the kale is exposed to sunlight, so the same conditions cannot be created in the freezer.
Storage
Since kale leaves are the main part of the plant, and they are also sensitive, everything should be done to keep them undamaged and fresh as long as possible. Kale is packed in deep trays, and for longer transport it needs to be covered with paper foil.
It is stored at temperatures from 0 to 1°C and relative humidity of about 95% and good ventilation. It can be stored in the refrigerator for up to 2 months.
When harvesting in continental areas, it can be harvested with the leaves and stacked in 1.5 m high piles and covered with leaves. Thus, it can keep freshness for a month. In the Mediterranean areas, late varieties of kale (autumn and winter kale) have good conditions in the field, but if the weather is warmer, it should be harvested and stored in time.
After harvesting, kale can be stored in the refrigerator for up to 30 days in a plastic bag.
Medicinal properties
Kale is one of the most healing foods in the world. It is rich in nutrients and at the same time has very few calories. One cup of raw kale has 20 calories, 1 g of protein and 4 g of carbohydrates. It has almost no fat, and what little it does contain are omega-3 fatty acids. It is an excellent source of vitamins C, A, B6 and K and dietary fiber, and the leading minerals are magnesium, potassium, manganese, copper, phosphorus and thiamin.
Eating kale strengthens immunity, protects the eyes, the health of the heart and blood vessels, reduces the occurrence of diabetes, improves digestion, strengthens bones, reduces almost all inflammations in the body, and affects the beauty of hair, skin and nails. It also protects against allergies and asthma due to the abundance of vitamin C, which strengthens impaired immunity.
Kale in cooking
Kale can be prepared in various ways, and in our country the most popular preparation is as a stew. However, kale can be steamed and potatoes and carrots added to it, after which, with a little olive oil and garlic, it becomes a delicious accompaniment to numerous meat and fish dishes.
Kale can be cooked as part of cream soup, stewed, can be added to pasta and risotto, and fresh kale leaves can be added raw to the blender, after which they become part of healthy juices. Kale is irreplaceable in the preparation of savory pies and puffs, it is part of fritters, and recently healthy kale chips are being made more and more often.
It can also be prepared fresh on a salad. Then a little olive oil, garlic and lemon juice are added to it. The combination of kale with cinnamon and currants is interesting.
When consuming fresh kale, make sure that it is not older kale, as it can be difficult to digest, and it is still recommended to boil it first. But not for too long, because with heat treatment it loses its medicinal properties and becomes soft. It is best to steam it for 5 minutes. Then it will soften, but it will still retain its green color and a large number of important medicinal properties.
Kale is prepared all year round, but most often in winter, since it is a winter vegetable, and that’s when it’s tastiest.
Interesting things
Kale originates from the north of Italy, more precisely from the Milan region. It was created from wild cabbage, and it is mostly grown only in Europe. It has been used in food since prehistoric times.
Photo: Efraimstochter / Pixabay