When to plant Calabrese in Sheffield

Sow seeds directly into prepared soil from 23rd April - 23rd May. Make drills 1 cm deep and space seeds 5 cm apart, thinning later. Cover lightly with soil and water well. Sow a new batch every 21 days across the displayed sowing window for a steadier crop.

Thin seedlings to the final spacing of 45 cm apart once they have two true leaves, around 7th May - 13th June. Remove the weakest plants, leaving the strongest to grow. Water after thinning to help the remaining plants establish.

Protect plants from pests as they grow from 14th May - 20th June. Use fine mesh netting to cover the bed, securing it well to keep out butterflies and birds. Add brassica collars to each plant to prevent root fly damage.

Apply a nitrogen-rich fertiliser every 28 days from 21st May to encourage growth. Use a liquid feed or granular fertiliser, watering it in thoroughly. Discontinue feeding when the central head begins to form.

Cut the main head when it's compact and before the flowers open, from 2nd July. Harvest side shoots regularly as they develop until 8th November. Keep the soil moist to reduce the risk of bolting during dry spells.