As landscapers, we know weeds are a constant fight. When they begin to sprout, it’s time to get our herbicides ready, many of which require a wetting agent for the best efficiency.
One common mistake you may be tempted to make is using a detergent such as dish soap as your preferred wetting agent. It’s easy to see why you may reach for that bottle of detergent, since it’s already available in your home.
I’ve learnt the hard way that it does more harm to my landscape and pockets in the long run.
In this post, I’ll show you why using detergents as wetting agents may not be as helpful as you may think, and why it may be the culprit giving the weeds some extra time to grow.
1. Chemical Composition
Detergents are designed to get rid of grime. They contain degreasers, fragrances, and other preservatives that may cause chemical reactions with the herbicide, reducing its efficacy.
Dish soap, for instance, may not be as effective as a wetting agent in pushing the herbicide into the plant system. It may leave an oily surface to look as though it works, but that’s about all it may do.
Wetting agents, on the other hand, are specifically formulated to reduce a liquid’s surface tension, thereby increasing its penetration into plant cell tissue.
2. Limits Application Maximization
When it comes to weeds like pigweed or marestail, herbicide application becomes a precise science. A detergent will likely bead up and run off, limiting plant contact and overall herbicide uptake.
The end result? Weeds that keep surviving, more respraying, and you become a frustrated gardener.
3. Detergents Are Not Label-Approved
Herbicide labels often specify the type of surfactant required. Using unlisted or unapproved products like detergents violates the guidelines, and this may get you into legal trouble in case of drift damage or negative environmental impact.
What We Recommend
Having observed that household detergents will likely provide satisfactory results, here are our recommendations for effective weed control:
- Use wetting agents approved for weed control and proven to increase uptake, such as soil wetting agents, non-ionic surfactants, and horticultural surfactants.
- Refer to the herbicide label for the recommended wetting agents and application rates.
Sticking to the agricultural wetting agent products can guarantee a win over weeds when it counts most.
Lead Editor for Insight Weeds.