When to plant Leeks in London

Around 18th February - 5th March, dig the bed well and work in compost. Leeks do best in moisture-retentive but free-draining soil, and a loose, stone-free tilth helps the stems grow straight.

Sow seeds thinly in modules or a seed tray around 19th January - 18th February, about 1 cm deep. Keep them at 15–18 °C and water gently so the compost stays moist but not sodden.

Move seedlings on when they are large enough to handle, from 9th February. Pot them into small modules or deeper trays so the roots can develop without crowding.

Set plants outside for a few hours a day before planting out. Do this over 21st March - 4th April so they adjust to wind, sun and cooler nights without checking growth.

Plant sturdy seedlings into deep dibbed holes around 21st March - 4th May, leaving just the base of the leaves at soil level. Water in thoroughly at once, then let the soil settle naturally around the roots rather than firming hard.

Keep the rows weed-free and draw soil up around the stems as they thicken. Start from 21st March and repeat as the plants grow, keeping moisture steady in dry spells so the stems stay tender and pale.

Lift leeks from 25th August once the stems are a usable size, then keep picking through 10th March 2028. Loosen the soil with a fork before pulling and take only the stems needed.