When and how to plant leeks?

Leeks are a much-loved vegetable in France. In fact, it is the ninth most widely consumed vegetable in France. Still known as the poor man's asparagus, it also goes by names such as porreau or poirette. Always eaten cooked, it has many health benefits. If you want to plant it at home, it's important not to do it like any other plant. Let's take a look in this article at when and how to plant your leeks in your vegetable garden.

Leeks: identity sheet

Leeks are plants belonging to the same family as onions and garlic, i.e. the Amaryllidaceae. It is widely eaten in France, particularly in soups or even gratins. With its scientific name allium porrum, it is renowned for its resistance, as most varieties are frost-resistant. What's more, it comes in more than 190 species, at least 26 varieties of which have been listed in France's Official Catalogue since 2014. So, when should you plant your leeks?

Leeks: the sowing calendar

Leeks are plants that can be planted at several times of the year. In fact, this is what makes it possible to differentiate a number of species among them. While some leeks can thrive in cold weather, others are better suited to the warmer seasons. A distinction is therefore made between summer, autumn, winter and spring leeks.

• Summer leeks
  Sown under cover or on a warm bed at the beginning of February, summer leeks can be harvested from the end of July.
• Autumn leeks
  Sow between late February and early March. To this end, they can be harvested during September, October, November and December.
• Winter leeks
  Sown between April and May, these leek varieties can be harvested from January of the following year until April.
• Spring leeks
  Spring leeks are sown directly into the ground in mid-August. They generally reach maturity between April and June of the following year.

Transplanting: a necessary stage in growing leeks

Leek growing is always done in two phases: first sowing and then transplanting, which generally takes place two to three months later.

How to sow leeks

To sow leeks, you can use a seed tray and place a seed in it every centimetre. This method is particularly suitable for summer leeks, which need to be sown very early in the season. Once sown, simply place them in a greenhouse or inside your home for the time it takes for the seedlings to sprout. Once the seedlings are a few centimetres tall, you can transplant them into their final location.

For autumn, spring or winter varieties, you can also sow leeks directly in the nursery. Prepare the soil well before sowing. It should be light and rich. Don't hesitate to cover your seeds with a few centimetres of potting soil.

When and how to transplant leeks

To transplant leeks, simply remove the small leek plants previously sown once they are a few centimetres tall and starting to grow slightly. Generally speaking, this takes 60 to 90 days after sowing. You can, for example, use a popsicle stick to push down just in front of the seedling, taking care not to damage it. Then pull it out and set it aside in a pot.

Once all the seedlings have been dug up, you cannot place them directly in the ground. To encourage them to take root, it's important to prepare the leek before planting. To do this, cut off the roots, leaving only 5mm to 1cm long. Also cut off the head 1cm above the leaf separation. All you then have to do is plant them out in a suitable spot, pushing them well into the soil with a knife or a tool like this one. Between transplanting and harvesting, you need to add another 3 to 4 months of growing time. Here's a video from André Abrahami to put all this into practice!

How long does it take to grow leeks?

As you will have realised, growing leeks will monopolise an area in your kitchen garden for quite a long time. The timing of sowing and transplanting will therefore depend on the variety of leek you want to grow. Personally, I prefer autumn and winter varieties. So I start sowing at the beginning of February, spreading out until March. I then transplant the leeks between May and August for a harvest in early autumn.

Note that leeks are reputed to be hardy plants. However, they will grow in cool, deep, humus-rich soils or substrates. It is therefore advisable to thoroughly amend the soil before planting in the vegetable garden.