Growing Leeks

Leeks are one of the most versatile vegetables in the garden. Eat them as a main course baked in the oven with a scattering of garlic, and a sprinkle of cheese toward the end of cooking, add them to potato and mixed vegetable soups, or use them as savoury pie and pastry fillings. Grow plenty of them, tucking them between roses and other ornamentals if you run out of space in the vege bed.

What Leeks Need to Thrive

Leeks have two main requirements: nitrogen and water. The first is easy to provide in an organic form by digging in plenty of well rotted animal manure and decaying seaweed. By ‘plenty’, I mean a wheelbarrow load of each for every 2 square metres of ground. A half barrow of mature compost for the same area will add texture to the soil and deliver the microbes that assist with the uptake of nutrients. A scattering of lime (a handful for every square metre) won’t go a miss. Water is essential as, if leeks dry out, they will quickly run to seed. Cover the ground between young plants with mulch (straw or pine needles work well) and water well on a twice weekly basis during dry spells.

Planting Leek Seedlings

Prepare the seedlings for planting by trimming their roots to about 2cm long (you can also trim a couple of centimetres off the tops if they are straggly). Makes holes in the ground, 10cm deep and 15cm apart, using a sharp stick. Place the young leeks in the holes but don’t back fill with soil. Instead, using a watering can or garden hose, water around the seedlings so just a little of the soil washes into the holes and covers the root section of the young plants. Successive watering and rain will eventually wash soil into the rest of the hole. Mulch the ground around the plants.

Feeding and Growing On

Leeks are gross feeders so, on a weekly basis until they are half way to maturity (you can decide for yourself when this is as leeks can be eaten at any stage from spring onion thickness to stems as thick as your wrist), feed with liquid manure.

Deprive leeks of nutrients and you risk their running to seed.

Harvesting and Cleaning

Some cooks are bothered by soil lodging between the layers of the stems and go to great lengths to protect them by placing toilet rolls over the neck of plants. Personally, I simply dice the leeks (or split them depending on how I plan to use them) and then rinse them well under a fast flowing tap (with the help of a sieve if the stems are chopped).

Growing Leeks Year Round

Leeks are very hardy and can remain in the garden through even the coldest of winters. In areas of severe cold, where ground freezes rock-hard in winter, it is possible to dig leeks earlier in the season and store them in a trench a glasshouse or in damp soil in a root cellar. Alternatively, plant your leek seedlings in the glasshouse in late summer once tomato vines have been evicted (or between the plants if the fruit is slow to mature).

Related reading:
Find more seasonal advice on our Vegetable Gardening page.