Botrytis: identify, prevent, control
Updated June 2026
Worst in cool, damp, humid conditions through autumn, winter and spring, March to September, and under glass.
Botrytis, or grey mould, is a fungal disease that coats flowers, fruit and stems in a fuzzy grey growth. It thrives in cool, damp, still conditions and rots strawberries, tomatoes, lettuce and soft fruit fast, both in the garden and in storage.
How to identify it
- Fuzzy grey mould on flowers, fruit, leaves and stems
- Soft, brown, watery rot spreading through fruit
- Dying flowers and fruit that collapse into mould
- A puff of grey spores when you disturb infected tissue
How to prevent it
- Space plants and prune for good airflow, especially under cover
- Water at the base in the morning and keep foliage and fruit dry
- Remove dead flowers, old leaves and rotting fruit promptly
- Avoid damaging fruit, since the fungus enters through wounds
Organic control, step by step
- Remove and bin all infected flowers, fruit and leaves as soon as you see them
- Improve airflow by thinning crowded growth and venting greenhouses
- Lower humidity around plants by spacing and avoiding evening watering
- Spray an eco-fungicide as a protectant in cool damp spells if pressure is high
- Harvest soft fruit promptly and handle it gently to limit storage rot
- Clear all infected debris and do not compost it
Plants it attacks
Track it in the app. The free Planting Season planner lists the pests and diseases to watch for on every plant in your garden, tuned to your region.