Botrytis: identify, prevent, control

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