Broccoli covers two rewarding crops: calabrese, which produces green heads in summer and autumn, and purple sprouting broccoli, a very hardy plant for early spring. Purple sprouting is especially valued during the hungry gap, when few fresh vegetables are ready.

When and how to sow

Sow calabrese in module trays from March to June for summer and autumn cutting. Sow purple sprouting broccoli from April to June, then plant it into its final bed by July for overwintering. Harden plants off before planting, spacing calabrese roughly 45 cm apart and purple sprouting 60 cm apart. Prepare fertile, firm ground in sun and avoid recently limed soil where club root is known.

Care

Water young plants during dry spells and firm soil around stems after windy weather. Mulch with garden compost to conserve moisture and suppress weeds. Net all plants against pigeons and butterflies, checking regularly that growing shoots are not pressed against the mesh.

Common problems

Cabbage white caterpillars hide among leaves and developing heads, while pigeons can remove young foliage overnight. Fine netting prevents both. Loose, club-root-prone soil can stunt plants, and calabrese may flower prematurely if drought, heat or delayed harvesting stresses it.

Harvest

Cut calabrese heads while their buds are close and green, before any yellow flowers appear; side shoots often follow. Harvest purple sprouting stems from February to April, depending on locality, when flower buds are tight. Pick repeatedly to extend the crop.

Growing Broccoli: frequently asked questions

When should I sow broccoli in the UK?

Sow calabrese in module trays from March to June for summer and autumn cutting.

What are common problems when growing broccoli?

Cabbage white caterpillars hide among leaves and developing heads, while pigeons can remove young foliage overnight.

When is broccoli ready to harvest?

Cut calabrese heads while their buds are close and green, before any yellow flowers appear; side shoots often follow.

General guidance for UK home gardens and allotments. Reference figures are typical values; your exact timing depends on your region, last-frost date and variety. Page updated 19 Sep 2026.