Thatch consists of layers of dead grass and moss which has been left to accumulate on the soil and must be removed in order to maintain a healthy lawn.

Scarifying can be done in one of two ways.

1. Little and often from March through to August. However, do not scarify during drought conditions.
2. Vigarous scarifying in the Spring and Autumn.

A powered lawn rake makes life a lot easier as scarifying by hand is hard work.

If possible, apply moss killer to the lawn a week or two before you scarify, so that the dead moss can be removed effectively.