Celery can be a difficult crop to grow, although self-blanching cultivars certainly help to take some of the strain out of growing.
The soil must be moisture-retentive and never dry out. As a result it is often better to grow the plants above a trench filled with plenty of organic matter.
The plants must never receive a check to growth so transplant, harden off and water properly.
Sow between mid-March and early April in seed trays or pots kept at at 15C (60F). Transplant the young seedlings when large enough to handle individually into 7.5cm (3in) pots or module trays.
Make sure plants are properly hardened off before planting out at the end of May to early June. Plant 23cm (9in) apart in a block to ensure the plants shade each other to aid blanching.
Water regularly during dry weather and feed every fortnight with a balanced liquid feed during the summer. A light dressing of a high nitrogen fertiliser or nitrate of soda after the plants have become established will help improve crops.
Plants are ready to harvest when large enough, between August and October, and before the first frosts.
