Water repellence and dry patch

Some soils, known as hydrophobic soils, are difficult to wet because they repel water. The infiltration of water into these soils can often be improved by applying a non-ionic surfactant; more commonly known as a wetting agent. Some companies rename this product ‘Drought Busters’ and totally misunderstand how wetting agents should be used and applied.

In hydrophobic soils, the soil particles are coated with substances that repel water, much like wax. In localised dry spots in turfgrass, the soil particles are found to be coated with a complex acidic material that appears to be the mycelium (growth structure) of a fungus.

Hydrophobia in soil is common in the golf industry, caused by a range of hydrophobic organic materials that form non-polar coatings on sand particles.

Non-ionic surfactants, or surface-active wetting agents are detergent-like substances that reduce the surface tension of water, allowing it to penetrate and disperse water in the soil more easily.

The down side of these products is that the lawn still needs water, lots of it to be honest, especially in the first few weeks after applying the product. The product will not make any difference to the health of the turf unless repeated applications are carried out.

In the past, wetting agents in the past were sprayed on using a dispersible tablet placed in a wetting gun. The product was applied all over the affected area with reasonable water pressure. (see below)

“Please do not be misled that wetting agents will save your lawns in a drought, because you may be a little disappointed”

Liquid wetting agents are now available and can be applied by walkover spraying equipment, but you will still need water. This product is not a ‘Drought Buster’, neither was it ever designed to be, but does relieve dry patch in managed turf when used as directed and managed properly.

If you have brown patches on your lawn, even after rainfall, please call us for advice and to have an area patch and electronically tested.

(Written by Andrew Manson, BSc Turf Science - Lawn Master Weald & Kent)