Leeks
An eternal favourite
In ancient times, leeks were grown along the nutrient-rich beds of the Nile. It is said that Emperor Nero ate large quantities to improve his singing voice. We tend to eat them for the flavour – but when leeks stand proudly in the countryside even though frost has mowed down other crops, it’s easy to burst into song.
Grow autumn leeks and winter leeks the same way
Autumn and winter leeks are sown and planted at the same time, but the winter variety is hardier and can be harvested for longer.
We sow leeks from December to May – usually in several rounds to ensure a long harvest. In the southern parts of the country, they can be sown directly outdoors. The seed germinates when the soil is 4 degrees centigrade. Soak the seeds in lukewarm water for 24 hours to speed up germination. Sow about 1 cm deep, with 3-5 cm between the seeds.
Our seedlings are always lanky to begin with. This is perfectly normal and is easily remedied by cutting them back to a height of about 5-7 cm a couple of times.
Leeks can often survive without replanting until they are sent out into the country. However, it is a good idea to water the plants a couple of times in the tray while they are growing.
Growing leeks on a balcony
Leeks can be grown on a balcony or patio. Use a deep pot. You may be able to fit three in one pot and add lettuce all round. The shallow roots of lettuce do not compete with the deep roots of leeks.
Cut the leek for tender stems
Once the risk of frost is over, the leeks can be planted out in the country. Harden off the plants first by keeping them outside during the day and under cover at night.
Keep 10-20 cm distance between each bulb and 40-60 cm distance between rows. Plant in nutrient-rich soil and feed regularly. Feel free to cover with grass clippings and other organic material. Just make sure to leave space right around the bulbs, so that they get air. In late summer, leeks start to grow, so it is particularly important to provide them with nutrients.
To get white, tender stems, leeks need to be cupped, and the easiest way to do this is to dig a trench about 15 cm deep in the ground. Then each onion is planted about 5 cm deeper than the bottom of the trench. As the bulbs grow, top them up with soil as you go along. Of course, it’s also possible to let the leeks grow without cupping. They will then be greener on the outer leaves and less mouldy.
Sometimes it’s easy to sow more seeds than you have room for. Leeks are one of the plants that can be planted densely at first and then thinned out. The small primroses are good in the kitchen, and the bulbs left in the country are given more space to grow bigger.
Leeks like to grow with other onions, celery and various cucumber plants. Co-growing leeks and carrots is particularly smart. The smell of onions chases away carrot flies and the smell of carrots chases away onion flies. Parsley is also good against onion flies. However, onions don’t like to grow too close to peas or beans.
Overwintering leeks
Some varieties of leek can survive the winter outdoors. To harvest during the cold months, keep the soil free of frost by using leaves, hay or straw. It is also possible to till leeks. To do this, dig up the bulbs and store them in a box or bucket with soil, sand or peat.
Leeks in cooking
It’s easy for soil to get stuck in the centre of the leek. Therefore, split the leek lengthwise and rinse before use.
The mild leek is easy to use in the kitchen, fresh and cooked. Try them in salads, stews, pies, casseroles and gratins. If the harvest is plentiful, you can both dry and freeze leeks. Dried onions can be ground into powder and mixed into a homemade herb salt.
Author: Johanna Damm
Fact-checked by Erik Hoekstra
Last updated 2022-10-14