Leek: planting, growing, caring for and harvesting

The leek (Allium porrum) is very easy to grow and it is a vegetable that can be planted regardless of the season by choosing the method that suits the climate. It is therefore perfect for starting a vegetable garden if you have no experience in the field because you succeed in growing it every time. Here’s how to sow or plant, care for and harvest the right garden leeks.

Sowing and planting leeks

It is between January 15 and September 15 that you can sow leeks, knowing however that at the beginning of the year, sowing in place is only possible in regions with an extremely mild climate because the soil temperature must be at least 12 ° C. In a harsh climate, seedlings are made under warm frames to be opened during the day during the sunniest hours as soon as the plants have emerged. These seedlings under layer make it possible to obtain early leeks. Whatever the case, the spreading of the seedlings allows harvesting from the month of June.

Sowing in the ground

Leeks like soils rich in organic matter, furniture, deep and humus and well drained because soggy soil is detrimental to it. It must be installed in a sunny area of the garden.

In the month of may, we start by preparing planks. This requires good hoeing to a depth of 20 cm in order to obtain a well-loosely aerated soil with a grelinette and which then suffices to weed manually and then level with the back of the rake. The leek is sown in place as follows :

  • Create furrows spaced apart from each other by about 20 cm,
  • Sow the seeds,
  • Cover with a thin layer of soil,
  • Water in rain and keep the soil moist afterwards.

Thinning takes place when the plants reach about ten centimeters in height and allows to keep the most vigorous knowing that they must be spaced 12 cm apart.

Sowing under frame

Leek seeds are sown at 1 cm from each other, covered with a thin layer of fine soil and then watered in rain. It is then necessary to install a protection as a tunnel. If you sow under a frame, it is necessary to close the latter in order to protect the seeds from the cold. Until the seedlings emerge, it is important that the soil is always moist, but one avoids excess water. The chassis is open a few hours a day when the sun is shining.

Sow in boxes

In this specific case, once the sowing is done, we spray the soil, taking care not to dig up the seeds and then place the container in a room. very bright where the temperature is maintained at 18 or 19 ° C. The potting soil must always remain moist. Germination is rapid since the young leek plants emerge in a fortnight. They will be transplanted first of all in pots where they will wait, always in the shelter, until May, when it is time to plant them in the garden.

If we wish avoid seedlings, we can simply buy your leek plants in garden centers because they are ready to be transplanted.

The transplanting leeks sown in January and February can be done from the very first days of April until the end of May, which will allow harvesting from October. As for the early leeks, which are harvested in spring, they are transplanted in November after sowing in August.

Maintain your leek culture

There is nothing too complicated about growing leeks.


In times of drought and high heat, it is necessary to carry out copious watering. But the soil should always be moist. However, excess water is avoided, which promotes fungal diseases and rotting.

Butter the earth

Butter the leeks regularly is essential and it is necessary to start before the winter period. This makes it possible to obtain very white and tender barrels.


Hoeing aerates the soil, allows weeding and limits water consumption.


When planting, add compost because leeks are greedy. During the first hoeing, it is also necessary to bury a fertilizer in the ground.

Parasites and diseases

Leeks can be attacked by various pests. Here are the most common and the solutions to prevent infestation or get rid of these unwanted ones.

  • Ringworm : insect net and tansy decoction,
  • Leek leafminer : insect trap or net,
  • Onion fly : decoction of tansy and / or maceration of tomato leaves for prevention.

Leeks are sensitive to mildew when the weather is both humid and mild. A spray of Bordeaux mixture or even horsetail manure helps prevent the installation of the fungus responsible for this disease.

We can fear the leek rust favored by the abundant rains in autumn. Likewise, leeks planted too tightly are vulnerable to it, which is why it is recommended to leave enough space between the plants and between the beds because this allows the air to circulate better. Fertilizers rich in nitrogen which promote rust should also not be abused. The horsetail decoction is an effective solution.

Crop rotation

It is strongly recommended to opt for the crop rotation every three or four years because this allows the earth to restructure and it is also a means of fighting against the installation of pests and diseases. We therefore do not always grow leeks in the same place.

Harvest the leek

Leek harvest takes place 5 months after sowing. Thus, the first can be tasted in July. But if you want to produce your winter leeks, it is obviously essential to choose hardy varieties because they are able to withstand low temperatures.

To tear the leeks, we use a fork-to-spade which allows the barrels to be fetched in depth without damaging them. All that remains is to lift them with the tool in order to remove them from the ground. In winter, the ideal is to harvest in sunny weather. The earth is easier to work than in heavy rain.

After harvest, we preserves his leeks from the garden in the refrigerator tray for 5 to 6 days. For a longer period, freezing is a good solution. Raw and cut into sections, they keep 2-3 months in the freezer. If you want to freeze them for a longer period, the leeks should be blanched for a few minutes. They are then cooled by immersing them in ice water and then drained. They must be perfectly dry to be placed in freezer bags or plastic boxes with tight-fitting lids. At temperature of -18 ° C, leeks keep perfectly for 5 to 6 months.

Finally, the cellar conservation is possible, provided that they are placed upright, in a kind of small trench, one against the other, then covered with a good layer of straw.