Bolting

Growing problem Plants run to flower and seed too early, so leaves and roots turn tough or bitter.

What to look for

A tall flowering stem rises from lettuce, spinach, rocket, coriander, beetroot, onions or brassicas. Leaves become bitter and the crop stops growing.

When: Mainly May to August, especially during heat and drought.

How to prevent it

• Choose bolt-resistant varieties and sow at the right time for each crop.
• Water regularly and mulch to keep roots cool and moist.
• Give leafy crops light shade in hot summer weather.
• Avoid sowing too early, as cold snaps trigger bolting in onions and beetroot.
• Sow little and often so there is always a fresh batch.

How to deal with it

• Harvest quickly, as bolted crops will not recover.
• Cut flower stalks off herbs such as basil, coriander and mint to extend picking.
• Let one or two plants flower to feed bees, or to save seed.

Crops it affects

🟣 Beetroot🥬 Celery🌿 Chervil🥬 Chicory🥬 Chinese cabbage🌿 Coriander🌿 Dill🥬 Endive🌿 Florence fennel🥗 Lamb’s lettuce🥬 Lettuce🥗 Mizuna🥕 Mooli (daikon)🥬 Mustard greens🥬 Pak choi🌿 Parsley🟣 Radicchio🥗 Rocket🍀 Spinach🥬 Tatsoi

If you choose to use any treatment, use only products approved for UK home gardens, follow the label and avoid spraying open flowers. See all pests and diseases.