Winter Geraniums Don't Like Dampness

The fungus mould (probably botrytis) developing on these geranium (pelargonium) leaves is caused by keeping them in too-damp conditions.

After lifting them from the garden and potting them in sterilized soil, I left them in a cold porch at the back of the house, adjoining the kitchen. Of course, every time I have opened the kitchen door, warm damp air has condensed on the cold plants (they don't have to be COLD, just COOLER), leaving a film of water on the surface, ideal for fungus.

After removing the infected leaves, I have now brought them inside the house. Hopefully they will recover when they dry, and we can take some cuttings.

I know I keep repeating it, but you do need to be very careful about damp geraniums over the winter months. This sort of thing happens in garages, as well, when warm wet air from the car settles onto cooler surroundings.

see also Strip Geraniums Almost Bare