Dry Patch is a term used to describe a condition whereby areas of the turf exhibit symptoms which are generally associated with moisture stress, but which are caused by the presence of an underlying water repellent (hydrophobic) soil. Dry Patch is not a new phenomenon but has been identified as an important maintenance problem within U.K. golf greens and lawns for over 50 years.
The expression of Dry Patch on the turf surface may occur in different ways in different areas. The most common form of symptom expression is a large patch/area of grass which is browned off or burnt in appearance. The symptoms usually appear during spells of dry weather and its appearance and severity is dependent on the type of grasses which are in the turf on your lawn, and where annual meadow grass predominate, (which are in most domestic lawns). A complete die back due to drought stress may occur in these areas if the soil beneath the affected area of the turf is snuff dry and resists all attempts at wetting. The symptoms of Dry Patch are invariably more severe on soils with higher sand content.
Drenching the turf with a hose will result in ‘ponding’ of the turf surface revealing the extent of the water repellent areas. Grass rotting is generally very poor in turf affected by Dry Patch, also the quality of the turf surface is adversely affected during the summer months as the thatch shrinks and swells during dry and wet conditions respectively.
CAUSES OF DRY PATCH
It is generally believed that factors such as compaction, slopes/high spot, poor irrigation coverage and excessive thatch are contributing factors to the severity of the problem.
TREATING DRY PATCH
To help reduce the symptoms of Dry Patch, a specialist wetting agent can be applied to the affected area. However, a D.I.Y. solution of mild soap detergent could be mixed and used on areas affected by Dry Patch if you’d prefer to try something at home. It wouldn’t be as effective as a professional solution, but there would be some improvement.
Spiking or slitting prior to a wetting agent application will help to increase the chances of it penetrating through the soil profile. If thatch or compaction are the main contributing factors then dethatching or aerating is strongly recommended.
In situations where Dry Patch is a major problem, wetting agent applications should be undertaken at 2-4 week intervals and watered in. Regular watering is key.