How to grow leeks

Leeks are an ever-popular class British winter vegetable. They’re wonderful grown in large open spaces in gardens and allotments but are also fantastic for growing in small batches in raised troughs and deep containers.

They’re versatile in the kitchen and can be harvested at times when your other crops are relatively quiet. Leeks are also simple to care for if you follow some simple advice.

When to sow leek seeds

  • For winter harvesting, sow leek seeds from mid-March to mid-April.
  • For spring harvesting, sow seeds in June.
  • For autumn harvesting, leek seeds will need to be in the ground in March.

How to sow leek seeds

Leek seeds are traditionally sown in a seedbed, which is an area away from your main growing site, ready to be transplanted at a later date; this enables you to use the main growing area for other faster-growing types of vegetables.

  • In your seedbed, sow each seed 0.5inches (1cm) below the surface in rows, with 6inches (15cm) between the rows. Water if the soil is dry.
  • Germination will happen after about two weeks.
  • If necessary, thin the seedlings by taking the weaker plants out to keep plants about 4inches (10cm) apart in the soil.

If you don’t have a seedbed or want just a handful of leeks, you can sow in small pots with one seed
in each pot.

How to transplant young leek plants

About 8 weeks after planting leek seeds, when the plants are pencil-thick and roughly 8inches (20cm) high, they’re ready for re-planting in your main growing site; this is called transplanting.

Roots of the young plants can be trimmed to about 2 inches (5cm) if needed – this makes it easier to re-plant them. You can also trim a few inches from the top of the plants if you do this.

  • Mark a line in the soil using string, attached to two stakes in the soil, to make a guide for your planting row.
  • Using a planting dibber or a small trowel, make a narrow hole 6inches (15cm) deep.
  • Place one plant in each hole but don’t fill the soil in around the plant.
  • Fill the hole with water. As the leek grows it will expand in the hole.

When to plant leek plants

Leeks can also be bought as young plants which will usually be sent to you around May and are ready for planting straight away. See above for how to plant young leek plants (How to transplant young leek plants).

How to water leeks

After the first watering when the planting hole is filled with water, you only need to keep leek plants watered if weather conditions are dry.

Leeks are self-sufficient if they’re not competing with weeds for water, so won’t require too much topping up with a watering can.

How to harvest leeks

You can start to harvest leeks when they’re small by gently lifting from the ground using a hand fork – this will give you a longer harvesting period.

Winter leeks can be left in the ground for many weeks and just taken as and when you need them.