Leeks are onion vegetables rich in vitamins and minerals, and are also known as leeks in many regions. The valuable ingredients not only have an effect on humans, but also contribute significantly to the care of the soil. Therefore, leek is an ideal preceding crop and is often used as a mixed crop partner. The lillia plant gets along well with cabbage, carrots, parsley, tomatoes and celery. Leeks, as the name suggests, belong to the leek genus, which is assigned to the amaryllis family.
Due to its intense and distinctive flavor, leeks are popular in regional cuisine.
Location and planting of leeks
Leek plants thrive best in a deep, humus-rich soil that should not be too dry. Waterlogging is to be avoided. An organic fertilization in autumn stimulates the growth of the plants and thus has a favorable effect on the yield. Since leeks or leeks are usually sown in the spring, it is optimal to sow green manure in the designated area the summer or fall beforehand. Lupines are suitable for summer, spinach for autumn. In the spring compost is still worked in. Since leeks are not particularly demanding on the climate, they thrive almost everywhere.
Depending on the variety (e.g.B. summer leek) leek can be sown in the greenhouse already in January. From the end of March, the young plants are then in the field. Leeks are planted with a row spacing of between 30 and 40 cm. In the row the distance should be about 15 cm. The onion vegetables should be planted as deep as possible, so that long stems can form. It is practical to make furrows about 15 cm deep, in which the young plantlets can be placed (see picture). The young plants must be watered vigorously. Regular mounding is important.
Autumn leeks can be sown directly in the bed at the beginning of April. Winter leeks, on the other hand, are sown from the end of July to the beginning of August. With winter leeks, piling up soil before the first frost is especially important.
A three-year crop rotation is to be aimed at, whereby onions and chives, which also belong to the Allium species, should not appear in the crop rotation. Since leek is considered a vegetable with very high root residues, the onion vegetable is optimal for the soil structure. Leeks are therefore often used as a preceding crop. As a neighbor to the leek is well suited oregano.
Care of leeks
In summer leek needs a lot of water. A mulch cover is therefore practical. On the one hand it keeps the moisture in the soil and on the other hand it largely suppresses weed growth. Organic fertilization with manure or compost is recommended.
To harvest leeks, it’s best to lift the plants out of the ground with a spade and then cut the roots just below the base of the roots. If the leek is to be used immediately, the leaves can be shortened. So that the leek can be processed fresh, it should in no case remain unrefrigerated for more than one day. In the refrigerator the onion vegetable keeps about one week. However, if the leaves are already beginning to yellow, the leeks should be consumed as soon as possible.
The harvesting point of the different varieties of leeks
- Summer leek : From July
- Autumn leeks : from September to December
- Winter leek : from mid-October until the next spring (April)
Diseases and pests
The enemies of leeks include the yellow streak virus, the leek moth, the leek leaf miner fly and the thrips. If the leek is affected by the yellow streak virus, this can lead to very large losses. The infestation can be recognized by the yellowish stripes on the leaves. An effective protection against the virus offers basically only the cultivation of largely resistant varieties.
The thrips and the leek moth are among the animal pests that can attack the leek. The tiny thrips suck themselves to the plant and, because they are very hidden, are usually only detected at a late stage. If the plant is infested with them, this can be recognized by the white-gray speckled spots. To effectively and quickly reduce a heavy infestation, washing the plant with lukewarm water has proven to be effective. If the plant is still in the pot, this is previously airtight, bspw. With a trash bag, tightly sealed to keep the pests from falling to the ground. Alternatively, protective nets have proven themselves, which not only help against infestation by thrips, but also keep away the leek leaf miner fly and the leek moth.
Allium plants like leeks are also attacked by lily bugs. However, the red beetles are noticed very quickly and can be fought without chemical means.