When to plant Celery in Sheffield

Sow seeds thinly around 21st February - 12th 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 14th 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 4th 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 9th 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 7th 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 7th May and keep going to 8th November. 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 30th July once the plants are well filled out. Harvest over 30th July - 8th November by taking what you need from each plant, or lift whole plants when they are fully sized before cold weather slows them down.