Growing Leeks from Seed to Harvest

how to grow leeks
How to grow healthy leeks

Leeks are a mild and tasty member of the allium family and are related to onions, shallots, garlic, chives, and scallions.

Unlike onions, leeks develop long, succulent stems rather than producing large bulbs. These stems are used as an onion substitute in many dishes. Leeks are cooler than onions. They perform the same jobs (use them anywhere you would a regular cooking onion) they’re sweeter, with a more delicate flavour – their own special ‘leeky’ flavour.

How to Grow Leeks

Grow in seed trays until about 20cm (8in) tall. They look rather like large blades of grass at that stage. Plant you leeks in full sun in fertile, well-drained soil. You can plant you seedling into into trenches or individual deep holes with black soil from the compost heap – make the holes using a dibber.

This is a better method than growing them in trenches, as the roots do not get into dead soil. When the plants are small, the space between the rows should be used for growing lettuces and radishes as catch crops. Leeks need regular watering and an application of seaweed tonic every two to three weeks to provide them with iron and selenium and promote quick growth and plump, tender stems.

Leeks don’t grow very well in a strongly acid soil preferring instead neutral to slightly alkaline soils (6.0 – 8.0 approx). If the pH (relative acidity or alkalinity) of your soil is not suited to the vegetable, then soil nutrients such as Nitrogen, Phosphorus, Potassium, Iron, Boron, Copper, Manganese and Zinc start to become unavailable, leading to poor crops. You can use a home soil test to determine your soils ph. By taking account of the test results you can then decide how much if any amendments are required to sort out the to pH of your vegetable garden soil.

When they are tall enough, earth them up to bleach the stems. Pull your leeks as and when you need them. Grasp the stem and carefully lever out the root from beneath with a hand fork, then shake off the soil.

Leek Growing Tips

  • Avoid planting leeks in soil that waterlogs or dries out rapidly
  • As you grow leeks for their leaves, ensure a rich soil with lots of organic matter
  • Grow giant leeks using wide and long PVC pipe
  • Take care when weeding because the roots and stems are easily damaged
  • Conserve moisture in a dry summer by spreading a one to two inch thick layer of grass clippings on the soil around the leeks