Leek is he althy, popular and thrives in your own garden: we show you everything about its origins and give tips on growing, harvesting and storing.
Leek (Allium porrum) has been valued as a vegetable since time immemorial. Egyptian wall paintings show that he was already very popular at that time. The Romans brought the leek from Egypt to Europe. It is believed that the leek evolved from the wild summer leek, which is also native to Egypt and other Mediterranean countries. Not only its Latin name suggests its relationship with the onion: smell and taste are clear clues! While older and traditional varieties still develop a slightly onion-shaped thickening on the base of the stem (above the roots), this is no longer found in modern breeds.
Many leek varieties are hardy. They can also be harvested in the following year until the end of April. After that it is usually too late, because the leek is already beginning to bloom. A round-oval umbel with many small white to pink flowers then develops on the long flower stem.
Synonyms: Leek, Welschzwiebel, Beef leek, garden leek, broad leek, garden leek (engl.)
Growing leeks correctly
Leek is one of the heavy feeders. It prefers loose and slightly sandy soils. The soil should be rich in nutrients and preferably deeply loosened before planting. Sunny and semi-shady locations are optimal for cultivation. Ordinary garden soils should be improved with plenty of compost (up to 10 liters per square meter). This not only improves the supply of nutrients, but also the ability of the soil to store water. In addition to nutrients, leeks always need sufficient moisture.
Depending on the bed plan, you can either prefer leeks or sow them directly outdoors. If you want to plant leeks as a previous crop, you should prefer the seeds on the windowsill for five to six weeks. From mid-April, the young plants can then be planted at a distance of approx15cm into the bed. Sowing the seeds of the early varieties outdoors should be considered from March. Later varieties that you want to harvest in autumn or winter can be sown between May and June. With a size of 15cm, the seedlings are pricked out and then transplanted at a distance of 15cm. The planting depth should be about 10-12cm, because you want to increase the white part of the leek.
Some leek lovers who are keen to experiment resort to the so-called hole planting method. Here, the young plants are allowed to grow longer before transplanting. Then a 20-25cm deep lock is cut into the loosened soil. Carefully lower the seedling into the hole so that the upper leaf tips are just sticking out of the soil.
During the growth phase, fertilizer should be applied three to four times at intervals of two weeks. A complete fertilizer is recommended here. Regular piling of soil around the plant will ensure a long white stem. The white part of the leek has a very mild taste and a particularly delicate texture.
You can find detailed step-by-step instructions for growing leeks here.
Leek comes in many varieties
The leeks we know are usually divided into summer and autumn/winter leeks. Not only the harvest time is decisive here: Most summer varieties are not sufficiently frost hardy to survive low minus temperatures.
You can find a comprehensive overview of varieties here: Leek: choosing the right variety for cultivation.
Summer Leek
- Bavaria: very early and fast-growing summer leek with long stalks and a high proportion of white; should be pushed forward and is suitable as a preceding crop.
- Earlier giant: the variety, also known as Major, is fast-growing, high-yielding and has a particularly long and thick stem. A very productive variety that clearly deserves a cultivation recommendation. Can be advanced and thus planted as a previous crop.
- Elephant: fast-growing variety with thick, short-medium length stems; not frost hardy and can therefore be harvested until November.
- Megaton (F1): very fast growing and long-stemmed variety with a high yield.
- Blue-green autumn: this leek variety is also often referred to and sold as Pandora or Ideal. Classic autumn leeks with long (up to 30cm) white onesshafts; very good yield.
- D'Elbeuf: proven and fast-growing autumn leek variety traditionally grown in France. The stems are relatively thick, but shorter than long-stemmed varieties like Bluegreen Fall. Very good aroma and reliable yield; blue-green foliage.
- Furor: French variety traditionally grown as an autumn leek. If planted correctly, the medium-length shaft is pure white and particularly delicate.
- Hannibal: classic and fast-growing autumn variety; medium length and very thick stems with a slight onion shape at the base (above the roots).
- Porbella: French variety harvested in autumn; Porballa is frost-resistant, has long and white stems; the leaves have a bluish cast.
- Tenor: another autumn variety from France with good stem characteristics and a slight formation of onions at the base; productive and aromatic; frost resistant.
Winter Leeks
- Blue-Green Winter: this variety is also known as Eskimo or Farinto and produces long and thick stems; particularly hardy and can be harvested in milder areas from October to March; very good aroma.
- Bleu Solaise: traditional and old winter variety from France, which is particularly robust and frost-resistant. The shaft is of medium length, thick and forms a slight onion shape at the base; the foliage has a distinct bluish cast.
- D'hiver de Saint Victor: autumn and winter variety also known as Siegfried in Germany; the shafts are quite thick, though not particularly long; very good aroma.
- Forrest: a particularly hardy leek selection with firm, long and thick stalks; good aroma and delicate texture. It is suitable for late planting, as it can be harvested until next April due to its winter hardiness. If you harvest the following year, you should have harvested all plants before flowering in May.
It should be just as interesting for all leek lovers that the pickled silver onions, so popular in Germany, were originally made from a wild leek species (Allium ampeloprasum). In German, these leek onions are called pearl onions. Silver onions are now made from special vegetable onions (Allium cepa). In commercial cultivation, the pearl onion is no longer of any importance. The elephant-garlic shares the same fate. Elephant garlic is a type of leek that is closely related to leeksforms large tubers that are very similar to garlic. However, the tubers usually only consist of a single clove. The taste of this type of leek is reminiscent of garlic, but it has a much milder taste and can be eaten grilled as an accompaniment to meat or antipasti.
What you need to know about harvesting and storing leeks
It is best to cut off the leek just above the roots. These remain in the soil and serve as organic nutrients. This is one of the reasons why the plant is so good as a previous crop. Late-ripening winter leek varieties can also be dug up at the end of November to the beginning of December and then thrown in loosely. So you have fresh leeks from your own garden all winter long. Leeks can also be stored in the refrigerator for up to two weeks. It is best to remove the top parts of the leaf (only available in stores anyway) and wrap the stem in a damp kitchen towel.
Ingredients and uses in the kitchen
The leek has a very high content of minerals, especially potassium, calcium and iron. Vitamins A, B1, B2 and C are also contained in these vegetables. In addition, leeks are rich in many secondary plant substances, such as sulphur-containing compounds, which are said to have an antibacterial effect. Leeks are usually steamed, sautéed or added to soups. The vegetables are particularly good in fish and mussel soups. It also unfolds its spicy aroma when baked with ham and cheese or as a quiche. Unlike most winter vegetables, leeks can also be eaten raw. Here you can cut the shank into thin slices and put it on bread or dress up a delicious salad.
Diseases and pests in leek cultivation
The two most important pests are the thrips (Thrips tabaci) and the leek moth (Acrolepiopsis assectella). While the former turns the foliage silvery-grey, the leek moth eats unsightly holes in the leeks.
Infestations with lice and onion flies can also occur from time to time. Covering the plants with a fine-meshed net usually helps against these pests. It is important that this is done in good time.
Fungi can also damage the leek, but fortunately they rarely occur.
Viral diseases are just as rare and are best prevented by long crop rotationbe able. Mixed cultures should be grown in your own garden anyway, because they significantly reduce the risk of a major virus infection.