What's eating my broccoli?

Broccoli is plagued by the same brassica pests as cabbage. Cabbage white caterpillars bore into florets and are hard to wash out; cabbage aphids build huge colonies on heads; root fly kills transplants. Clubroot soilborne disease is a long-term threat. Insect-proof mesh from planting is non-negotiable for clean harvests in most UK and US gardens.

Holes in leaves; caterpillars hiding inside developing florets making the harvest unusable if undetected Cover with fine insect-proof mesh immediately after transplanting; hand-pick; apply Bt spray targeting small caterpillars early in the season

Dense grey colonies buried in the floret — invisible until harvest; honeydew and sooty mould on heads Use a strong water jet on heads at harvest; spray insecticidal soap earlier in the season before heads form; check regularly from mid-summer onward

Transplants wilt and die despite watering; white maggots in roots; entire plant can collapse Fit brassica root collars (card or rubber disc) at transplanting; grow under fine mesh; practice 3-year minimum rotation away from brassicas

Small irregular holes in leaves; tiny pale caterpillars on leaf undersides; can develop resistance to Bt Use Bt spray while caterpillars are small; rotate Bt with spinosad to reduce resistance; row cover is the most reliable prevention