Grey mold
How to get rid of the fungus
This fungal disease is recognizable as a grey, dusty spot on the plant. The fungal spores are omnipresent. Infection occurs via dead plant parts, usually from weak plants.
Treatment and prevention
Dead plant parts should be removed as a preventative measure. Watering with nettle or horsetail manure can help. Other biological plant protection products are available from specialist retailers (e.g. DIY stores).
Rasbak, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons
