How to Grow Leeks

Leeks are a great vegetable to grow in cooler climates. Compact, versatile, easy to grow in different soil conditions, they’re a cornerstone of any vegetable patch.

Tasty and succulent to eat, leek foliage is also prized as an ornamental feature of borders, or around the edge of your allotment. Here’s our guide to growing your own leeks.

When to plant Leeks

Seeds should be planted out in the spring, between March and April. Plug plants can be planted out in late May. Leeks prefer well-draining soil in a sunny, sheltered location.

How to plant Leeks

Prepare the soil early, preferably over the winter. Dig over thoroughly, removing stones and weeds, forking in well-rotted manure to improve moisture retention. The soil can be heavy and the leeks will still grow well – however, ensure that drainage levels are maintained. One method of doing this is to mix in some horticultural sand.

A week before sowing, rake in a little general fertiliser. Plant rows 30 to 35cm apart. Create a shallow groove or furrow around 1cm deep and sow the seed thinly along this row.

Cover over the row with soil and gently water them in well. In just over a month, seedlings will have grown up and started leafing – when they have three leaves, thin the plants down to 15 cm gaps. You can replant the thinned out seedlings elsewhere.

If you’re planting out plug plants, position each plant into individual holes (around 20 cm deep) in late May and water into each hole – do not fill the hole back in. The soil will be drawn over the roots while leaving space for the leek stems to grow. Keep the leeks watered well, and harvest from September on.

Harvesting Leeks

Depending on which variety you are growing, harvesting begins in the late summer. Use a fork to carefully lift out the stems.

Some varieties can be harvested through into the winter when few other home-grown vegetables are available from the garden.

Through the year

Keep the row of leeks well weeded, while not accidentally picking out the leek seedlings which look grass-like. There is no need to harvest your crop all at once – you can leave your leeks in the ground until they’re needed.

When choosing the site for your leek rows bear this in mind.

Handy tips

Use mulch around the row of leeks to aid water retention over dry spells.

Don’t plant leeks in exactly the same location year on year as this will help the build-up of soil-based pests.

If your leeks are turning out stems that are slightly tough and coarse to eat, this may be because the soil you are growing them in is too rich – use well-rotted manure to prepare the ground, and when raking in the general fertiliser before sowing, use roughly 60 g per square metre. Further feeding or fertilising is unnecessary.

Ready to plant your own vegetables now you know how to grow leeks? Take a look at our vegetable seed collection.