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How To Grow Leeks From Seed (With Step By Step Pictures)

Leeks are one of the few vegetables that can be harvested all the way through the winter, making them versatile and valuable. Here’s how to grow leeks you can enjoy practically all year long.

freshly picked leeks.

Leeks are very easy to grow, and since they are a member of the allium family, they can be used as a substitute for onions in many recipes.

How To Grow Leeks

How to grow leeks

Prepare the soil for planting leeks

Leeks do not require much soil nutrition, so adding manure to this part of the vegetable garden is not worthwhile. Digging the leek bed and adding garden compost and leaf mold is best. Adding some humus will assist with drainage. They also like a dressing of Fish, Blood, and Bone fertilizer.

How to plant leeks from seed

Sowing leeks couldn’t be easier. Simply scatter some seeds in a 6″ pot filled with general-purpose compost and water and keep them under glass, either in the greenhouse or on a warm windowsill. Sow seeds in March to give the leeks a good start, but even May-sown leeks will do well.

Below is a rare type of leek called Bleu De Solaise.

Leeks germinating in a pot

Once the leeks have nearly reached the thickness of a pencil, usually in June, prepare them for transplanting in your chosen bed by hardening them off. Do this by putting them outside during the day for a few days.

Leeks in a pot, ready to transplant to the garden

To separate each leek seedling, you might find it helpful to soak the roots in water to untangle them. Use a bucket of water to help untangle roots.

Soaking young leeks in a bucket of water to untangle their roots to plant in the garden

Separate each baby leek to plant out in the garden.

Separate leek roots in preparation for planting

Some books will tell you to trim the leek root and stem, but I’d rather not—your choice.

A close up of a hand trimming leeks

To plant the leeks outside, once you separate the plants, dig some holes 6″ deep and space leeks about 6″ apart. You can dig these holes with the handle of an old spade.

Making leek holes

Do not fill hole with soil, just water them in.

Watering newly planted leeks

Tips for growing leeks

The secret to growing great leeks is keeping them weed-free, as weeds will seriously stunt their growth. Unfortunately, the only way to weed leeks is by hand, as a hoe will cause more damage than the weeds.

If you are planting a lot of leeks to help with weeding, leave a larger gap every 4 to 6 rows to have somewhere to kneel and get between the plants.

Watering your leeks during a drought is very important.

The white part near the root of the leek is caused by blanching, and the more of the plant that is out of the sun, the larger the blanched part.

To achieve this, some growers will draw up soil around the leeks as they grow, but if you are not careful, you can quickly get soil in the leaf tops, which will be incorporated into the leek itself.

Another way of blanching would be wrapping the leek in a cardboard sleeve. A toilet roll cut length-ways held on with an elastic band works well 😉

Leek pests and diseases

Leeks are mostly problem-free, although once, we got our leeks trimmed right down to the ground by a rabbit. Mind you, this did not cause any losses as the leeks continued to grow.

Another possible problem is rust, which, again, is rare. If you are unlucky enough to get an outbreak of rust, then unfortunately, there is no cure, and you will need to buy a rust-resistant variety next time.

How to harvest leeks

Harvesting leeks can be done starting in September. Lifting leeks is easier if you lever them up with a fork. They are available through the winter, although they can be difficult to harvest if the ground is frozen.

If you expect a cold snap, lift a dozen or so leeks and place them upright in one lightly filled hole; they will be much easier to harvest from there.

If you have sown too many leeks and have many leek seedlings, plant them back in a pot and use them instead of spring onions.

Cooking with leeks

Leeks are incredibly versatile: they can be used as a substitute for onions, and they work well in Asian cooking, soups, and more traditional dishes.

One all-time favorite way to serve them is braised. Just soften the leeks in butter, add a dash of wine, and reduce, then add cream and some grated cheese and bake in the oven.

Other ideas to use leeks would be Leek and Potato Soup (this is my favorite), Chicken and Leek Pie, and of course Cock a Leekie.

How to grow leeks.

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