When to plant Celery in the UK

Sow seeds thinly around early March to late March on the surface of fine seed compost, then just cover with a light dusting of vermiculite. Keep them at 15–18 °C and never let the compost dry out.

Prick out seedlings once they are large enough to handle, from late March, and move each one into its own small pot. Keep the young plants growing steadily and water gently from below if possible.

Pot on when roots fill the small pots, from mid-April. Use a richer mix and keep the plants moving without checks, as stunted celery rarely recovers well.

Harden off over about 15 before planting out, from mid-April. Stand the plants outside in a sheltered spot by day and bring them back in at night at first, then leave them out for longer each day.

Plant out from mid-May into rich, moisture-retentive soil once the danger of frost has passed. Set plants 30 cm apart, water in thoroughly at once, and protect them with fleece or cloches if cold weather returns.

Start from mid-May and keep going to late October. Water deeply in dry spells and feed every 14 days with a balanced liquid feed to keep growth steady and stems crisp.

Cut the outer stems from early August once the plants are well filled out. Harvest over early August to late October by taking what you need from each plant, or lift whole plants when they are fully sized before cold weather slows them down.