Dry Patch

Dry patch occurs when the soil becomes water-repellent, it is unable to absorb water even in wet weather. The grass dies as it becomes drought stressed, and patches of pale dead grass appear in the lawn. 

Fungi similar to those seen in Fairy Rings (Type 1) grow through the thatch layer and amongst the roots, and coat the particles of soil with water-repellent chemicals. Water is unable to reach the roots as it will either run off or sit on the surface of the soil. The grass suffers from severe drought, turning from a darker green colour to brown. Compaction and a thick accumulation of thatch may make a lawn more prone to dry patch. 

Dry patch can be controlled by scarifying to remove the accumulations of thatch, aerating the lawn and feeding at appropriate times to promote growth and the development of a strong root system. 

Scarification should be carried out in Spring or Autumn and, where necessary, bare patches overseeded. This should be followed by aerating or spiking the soil as this will allow water to penetrate, and reduce compaction. In early summer an application of a wetting agent will help moisture penetrate more easily. Spiking and the application of a wetting agent will need to be repeated on a monthly basis for three or four months. 

In severe cases that do not respond to these treatments, the turf and soil will need to be removed, replaced with fresh soil and the area reseeded.