Crops from 24 weeks after sowing. For the best crops, dig and manure the soil in autumn or early winter, applying a light dressing of lime early in February and a week before sowings. Sow in grooves 1.25cm deep, 23cm apart. Thin plants out finally to 15cm apart. For exhibition onions, sow under glass December-January, transplant seedlings into boxes or pots and harden off for planting out in April.