When should I sow broccoli in the UK?

Calabrese (the standard green broccoli): March to June in modules; successional sowings every 3 weeks. Crops from July to October. Purple sprouting broccoli: May to early June only — these are biennials that crop the following February to April. Don't mix the timings; the two types are essentially different crops with different sowing windows.

What's the difference between calabrese and purple sprouting broccoli?

Both are Brassica oleracea var. italica but in distinct cultivar groups. Calabrese: one big central head, summer-autumn cropping, the supermarket standard. Purple sprouting: many small purple-budded shoots, late winter–early spring cropping (February–April), the allotment treasure. Sprouting types are hardier (H6 vs H5), much longer to mature (10+ months), but crop when nothing else is in season.

My broccoli flowered before I could pick it — can I still eat it?

The buds are edible up to the moment they open into yellow flowers; once flowering, the heads turn bitter and stringy. Catch heads before flowering by checking daily once they look full — the window is 2–3 days, easy to miss in a hot week. If the central head bolted, leave the plant — side-shoots from leaf joints often produce smaller usable heads.

Why are my broccoli heads tiny?

Most common causes: planted too close (give them 30 cm calabrese, 60 cm sprouting), water stress (broccoli stops heading in drought), nutrient-poor soil, or a calabrese variety unsuited to the UK climate. Choose F1 hybrids bred for UK conditions; water deeply through July–August; feed mid-summer.

When can I pick purple sprouting broccoli?

Late February to mid-April from a sowing the previous May. Cut shoots when buds are still tightly closed and purple. Continuous picking — the more you cut, the more shoots form. A single plant gives 6–8 weeks of picking. Cropping ends when the plant runs out of energy and bolts.

How do I stop caterpillars on broccoli?

Net firmly with 5 mm enviromesh on hoops from transplanting through October. Cabbage white butterflies lay tiny yellow eggs in clusters on the undersides of leaves; once hatched the caterpillars eat fast. Inspect weekly for eggs and rub them off. Bacillus thuringiensis (Bt) spray is an organic-approved last resort.

Brokkoli

Brassica oleracea var. italica

Sow calabrese (the supermarket-standard broccoli) from March to June for summer to autumn cropping; transplant 30 cm apart in firm fertile soil. Broccoli is hardy (RHS H5) and reliable in UK conditions but heads bolt quickly in heat — successional sowings every 3 weeks keep the supply going. Cut the central head when buds are still tightly closed; side-shoots crop on for weeks afterwards if you keep picking. Net firmly against cabbage white butterflies through summer. Purple sprouting broccoli (the overwintering type, different cultivar group) is hardier (H6), sown in May and cropping the following February to April when little else is in season. Net pigeons in winter for sprouting types.

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