Sow seeds from February to April 3mm (1/8in) deep in a good seed compost. Germination takes 21-25 days at 20-25C (70-75F). Sealing in a polythene bag after sowing is helpful. Lower the temperature after germination. When large enough to handle, transplant the seedlings 4cm (1½in) apart into boxes. Gradually acclimatise to outdoor conditions and plant out in June 30-35cm (12-15in) apart in full sun and well drained soil.Keep well watered especially in dry spells. Hoe regularly and remove any side shoots which may form. Harvest the roots in October-November. In late November lift any remaining and store in damp sand in a cool dry place for winter use.