We believe that wetting agents are the most important product to use on your lawn. If we had to pick one product to use, we would choose wetting agents over any other product, even fertiliser.

In the Canberra and Queanbeyan region, our climate extremes are not quite suited to either cool season grasses, or warm season grasses. Our climate can be too hot in Summer for cool season grasses and our Winters are long, resulting in fully dormant warm season grasses. Hot and dry periods of weather are not uncommon. During these times, wetting agents become crucial to sustain your lawn, particularly cool season lawns, such as Fescue, Kentucky Bluegrass and Rye which is common in our region.

There are different types of wetting agents that have unique qualities, and can generally be grouped into three categories –

  • Penetrant
  • Spreader/sticker
  • Humectant/retainer

Some wetting agent products will combine two or more different types of wetting agents to get the most benefit from their unique qualities. There are many different options available but at Tommy’s Turf we like to use a liquid wetting agent called Hydroforce Rapid. Hydroforce Rapid can be used for all three of the below uses, depending on the application rate. 

The three main reasons why we use a wetting agent

  1. Assist penetration. Penetrants are used to assist penetrartion through a thatch layer or compacted surface to allow water to reach the rootzone where it is needed. A natural build-up of thatch in a lawn will act like a sponge to hold moisture and prevent it from effectively reaching the rooztone. Using a penetrant type wetting agent will reduce surface tension of the water to let it flow freely through these layers, ensuring more efficient use of water. This can be particularly helpful when your lawn is on a slope in combination with a compacted surface, causing run-off. 
  1. Improve the wettability of hydrophobic soils. Hydrophopbic soils may present as localised dry spots in lawns, these are spots in the lawn that despite getting the same amount of water, suffer moisture stress. You will often see patches in the lawn that are wilting when the rest of the lawn is not, the signs of wilting to look out for are a blue tinge of colour and visible footprints when walked on. Turf that is not wilting or suffering from moisture stress will generally stand back up when walked on and footprints won’t be as visible. Using a penetrant and retainer will help to uniformly distribute moisture through the soil profile and hold it there for a longer period of time to prevent these localised dry spots from occurring.
  1. Improve the efficiency of herbicides and foliar fertilisers. Using a “spreader” or “sticker” type of wetting agent will assist in sticking a herbicide or foliar fertiliser to the leaf of the turfgrass or target weed, rather then beading off the surface of the leaf. This can also be said for “penetrating” wetting agents and improving the efficiency of soil drenches or products such as Acelepryn, which need to be watered into the soil profile and will not be effective if they do not pass through a compaction or thatch layer.
  • When Hydroforce Rapid is applied at a low rate and watered in, it will aid penetration.
  • When it is applied at the higher rate and watered in, it will help prevent the occurrence of localised dry spots caused by hydrophobic soils by aiding penetration and also by retaining moisture in the soil profile. The higher the rate, the longer it will retain the moisture.
  • When it is applied at a low rate and left on the leaf, it will improve the efficiency of herbicides and foliar fertiliser applications, acting as a “sticker”.

Granular wetting agents

Wetting agents are also available in granular form which can make for an easier application if you have a granular spreader and don’t own a sprayer for liquid wetting agents. Granular wetting agents are usually a liquid wetting agent coating applied to an inert granule such as leonardite. We sometimes use a product called CalWet which is a Gypsum prill with a wetting agent coating. CalWet is particularly helpful for the heavy clay soils in our region with the added benefit of Calcium for your lawn.

By Tom Griffin