How to grow leeks

About leeks

Leeks prefer a sunny, sheltered site with well-drained soil. As they will sit in the soil for a long time, they're an ideal crop for the allotment, although many have fantastic foliage that makes them an ideal vegetable to grow in flower borders or an ornamental potager.

What to do

Soil preparation

• Choose a sunny, sheltered site with well-drained soil.
• If possible, prepare the soil for planting in the winter. Dig the site well, removing weeds and working in plenty of well-rotted manure to improve its ability to retain water.
• Leeks can be planted in heavy soil, but improve the drainage by mixing in some horticultural sand.
• This is a hungry crop – spread a general balanced fertiliser over the soil a week or so before sowing and rake in. A rate of 60g per square metre is ideal.

How to sow

• The easiest method is to sow seed directly into the soil between March and April. Alternatively, you could cheat and buy ready-grown seedlings, many nurseries offer a good range. By careful choice of varieties you could have an ample supply of leeks to harvest from mid-summer until the following spring.
• On the allotment, seeds are best sown in rows, 30cm apart. Mark a straight line and use the corner of a rake to make a shallow groove in the soil, about 1cm deep. Sow seed thinly along the trench, cover with soil, water and label. When seedlings have three leaves each, about four to five weeks later, thin to leave plants every 15cm - the seedlings you remove could be used to plug gaps elsewhere.
• Alternatively, buy ready-grown plants. They will arrive as young seedlings during May and June, ready to plant out straight away. To do this, make a hole with a dibber, 20cm deep, and drop a seedling into each. Using a watering can, fill the hole with water and allow to soak away - this will draw enough soil over the plant to cover the roots and produce wonderful blanched stems as the leek grows.
• Keep plants well watered, especially during dry spells and harvest from summer onwards.

Aftercare

• Bare soil is an open invitation to weeds, so carefully remove any stray seedlings, avoiding the grass-like young leek plants - it's essential to clearly mark the row so you don't remove plants by mistake.
• Keep plants well-watered, especially during dry spells - a mulch will help to retain moisture over summer.

Harvesting

• Depending on which variety, your leeks will be ready for picking from summer, although the most useful types are those that can be picked over winter, when there's little else in the vegetable garden.
• Harvest leeks by lifting carefully with a fork, aiming to avoid damaging neighbouring crops.

Five to try

• 'Musselburgh' - winter hardy with white stems. Pick from December to April.
• 'The Lyon' - autumn variety with mild-tasting long stems
• 'Monstruoso de Carentan' - French heritage leek with short stems from October to January
• 'Pandora' - glaucous leaves and long white stems. Crops between September and January
• 'Autumn Giant 2 Porvite' - tasty, white stems