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Wetting Agents

Thursday 17, Oct 2019


In the last edition (Volume 21.1 – Jan-Feb 2019), Australian Turfgrass Management carried a USGA-authored piece on wetting agents and the important role they play in agronomic programmes. The article looked at the numerous agronomic and environmental factors that influence wetting agent performance and highlighted the importance of testing and evaluating products to determine which is best for your facility.

To provide some local context to the article, ATM canvassed a number of Australian superintendents to get an insight into their use of wetting agents and the practices and products they employ.

ATM asked the following questions;

What sort of wetting agent programme do you have in place at your facility and what have you found works best for your situation (or what hasn’t worked)? 

How has your use of wetting agents changed over time and how do you go about determining what is the best wetting agent for your situation?


The following is a snapshot of responses that ATM received…

David Johnson

Patterson River GC, Vic

I attended a seminar titled ‘Wetting agents and their effects on putting greens’ at the GCSAA conference in San Antonio last year (2018) conducted by Doug Karcher (University of Arkansas).

His research changed the way I use wetting agents and opened my eyes in regards to hydrophobic sands and soils and water retention. 

Dr Karcher’s research found that two initial high application rates of a wetting agent in the first month at the start of the warm season, with 5mm of watering in, followed by high single monthly applications should be enough to break water retention and penetrate into the soil profile to the roots of the plant. 



With regular irrigation, either by sprinklers or hand watering, this should give you an optimum moisture level of between 15-20 per cent. Anything lower than 15 per cent moisture is heading into local hand watering stage and 11 per cent moisture or lower is at wilt point. 


Dr Karcher also found that this practice also reduced his irrigation by 20 per cent over the warm summer months.  Moisture meters were also recommended to keep a close eye on moisture percentages and local dry patches even though the green may look fine.


I started this practice late in the summer last year when I got back from the USA and have continued the same practise through the recent summer period from September.  I have found that although it has been an indifferent summer period, with rains in the beginning of December followed by long dry spell, the signs are very positive.


Localised dry patch seems to have been minimised and the moisture levels seem to be steady at around 15-25 per cent.  Irrigation water usage is the one I’m keen to keep my eye on though, but I’ll have to wait until the summer irrigation period is over before evaluating whether or not usage has dropped.


To read more insights from superintendants across Australia click here.