Symptoms
Young shoots and leaves turn brown and decay - typical fuzzy grey mould may appear on the affected foliage, but often the damage appears slimy. The fungus may also cause a soft, mushy rot of the bulb.
Cause
It is due to one of the several grey moulds, or Botrytis species, that damage bulbs and other plants. The fungus can lie dormant in the soil or dead bulb scales in the form of small, black resting bodies called sclerotia. These germinate in late winter and the fungus infects the emerging leaves and spreads to the bulb scales.
The disease often occurs where infected snowdrops have been grown before and is worst during wet springs.
Non-chemical control
- Dig up affected plants, and bin or burn.
- Before planting, inspect snowdrops carefully for the black spots of the sclerotia on the outer bulb scales.
- Plant healthy snowdrops on a fresh site.
- Choose snowdrops that show resistance to grey mould: Galanthus nivalis Scharlockii Group, Galanthus plicatus.
Chemical control
There are no fungicide treatments for bulbs in the ground, but dusting lifted bulbs with sulphur dust (Vitax Green or Yellow Sulphur) may be helpful.