White Ash Substance In Lawn.

The white ash like substance often found in older lawns is a type of fungus feeding on the thatch layer in the grass.The thatch is a layer of dead roots and grass blades which form an organic layer at the base of the grass plants. This fungus is natural and not normally a problem unless it forms a barrier to stop water soaking into the lawn.In this case it needs to be broken up by lots of spiking with a garden fork.There is not chemical cure.