Pro Lawn Help

Dry Patch

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 of U.K. golf greens and lawns for over 50 years.  

SYMPTOMS 

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.  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. 

ALLEVIATION OF DRY PATCH 

At this present time the only means of reducing the symptoms of Dry Patch is to apply a wetting agent to the affected area.  It is also known that soap and mild detergent solutions have been used to facilitate the entry of water onto the Turf affected by Dry Patch. Spiking or slitting prior to the wetting agent application will increase its movement through the soil profile and better control. The situation where Dry Patch is a major problem wetting agent treatment has to be more intense with applications completed at 2-4 week intervals and forced into the Turf by hand watering. 

In order to alleviate this problem long term, you must, firstly, address the conditions causing the Dry Patch. If thatch or compaction are the main contributing factors then dethatching or aerating is strongly recommended.