Fusarium Patch & Snow Mould

Fusarium Patch
This is another very common lawn disease, seen mainly, but not exclusively, during the autumn and winter months. 

This is a cool weather disease and enjoys persistent drizzle and foggy/misty conditions.

Symptoms appear as small, circular, yellow patches which spread up to about 30cm in diameter.  Once established, the patches turn a yellow/brown colour and in severe cases can kill the grass.  After the disease becomes inactive, the area appears pale and straw-like.

Lawns that have a high thatch layer and poor drainage, as well as enclosed lawns with little air movement, are the most susceptible to Fusarium.

Closely related to Fusarium is Snow Mould, another cold weather disease that  thrives in lawns with poor air circulation.  This fungal disease spreads rapidly during cold weather, especially under a blanket of snow, when air circulation is impossible.  When snow settles on a lawn for any length of time, it incubates the disease which can only be seen once the snow has melted away.

The fungus produces white patches which, in severe cases, can turn pink.  To avoid this disease, try and keep snow off the lawn.  If this is not possible, it can be treated with a special fungicide.