Grey mould (botrytis) is a fungal disease that attacks a wide range of plants – especially those growing under cover in greenhouses that are kept too humid from autumn to spring. But it will attack other plants at other times of the year.


Botrytis (Grey Mould) is a plant disease often found on indoor cyclamen and outdoor flowers, such as dahlia and chrysanthemum kept in humid conditions.


A grey fluffy mould found on leaves, petals and the base of stalks.

Treatment and control

Pick off the affected part of the plant and reduce humidity by increasing space between plants and air movement. Burn plants that are severely affected.

Avoid overfeeding with a high nitrogen plant feed as this encourages soft lush growth that is more susceptible to attack. High potash feeds can strengthen plants.

No fungicide treatments are available to home gardeners.

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