Homemade Wetting Agents for Lawns (A Few Ideas)

With water conservation becoming more and more of a necessity, wetting agents can make it easier to have the lush lawn you want without running up your water bill or running into a water restriction. Commercial wetting agents, however, can be pricey or hard to find- especially if your lawn already has all of the fertilizer it needs. The following wetting agents for lawns are a few of my favorites- they’re easy to come by, inexpensive, and easy to use.

What is a Wetting Agent?

A wetting agent is a “surfactant” or a substance that lowers or “breaks” the surface tension of a liquid, allowing it to spread or be absorbed more easily. Wetting agents are used in lawn care, for example, to apply foliar feed, liquid fertilizer, or to deliver more water to plants faster than applying the water without a wetting agent. During droughts, wetting agents are used to get more water into a lawn or other plant with less water being “lost” in the process.

Homemade Wetting Agent for Lawns – A Few of My Favorites

There are only a handful of “homemade” or DIY wetting agents that are biodegradable and good for lawns. Of these, the following four are the best options. All of them are inexpensive and worth having around, especially in hot climates or places with sandy or rocky soil.

Baby Shampoo

Baby shampoo is a readily-available product that makes a good wetting agent as it contains at least one surfactant and few other additives that may irritate your plants or harm your lawn. Baby shampoo is already diluted enough that it can be applied directly to your lawn with a sprayer.

SLS and SLES (Sodium Lauryl Sulfate or Sodium Laureth Sulfate)

Sodium lauryl sulfate or sodium laureth sulfate are both surfactants found in commercial personal care and beauty products. It’s a chemical that can be purchased on its own for about $5 a pound; less if you buy in bulk. For the price, this is the least expensive DIY wetting agent here with the fewest additives. SLS is typically mixed at a ratio of 1 ounce of SLS to 1.5 gallons of water before being applied to lawns or potted plants in a thin, even spray.

One thing to note about SLS/SLES or any of these other options is that handling them over time and allowing them to come into contact with your bare skin can cause irritation. Always wear gloves with a moisture barrier, even when handling “safe” chemicals and fertilizers for an extended period.

Humic and Fulvic Acid

Humic acid and fulvic acid are complex organic acids typically found where things are decomposing. Compost and manure teas are naturally rich in both of these acids, making them ideal additions to your lawn care routine if you have access to high-quality compost or manure. Both of these organic acids are natural wetting agents and humectants. This means they can help break down water repellent coatings from hydrophobic soils, as well as help that soil retain more moisture in the future.

Agar Solution (Agar Agar or Seaweed Gelatin)

Agar is a type of granular seaweed gelatin that can break the surface tension of liquids as well as condition the soil and provide nutrients. This makes it an ideal candidate for use as a homemade wetting agent for lawns. Choose an agar mix with no added sugar or other types of gelatin mixed in.

Mix the dry agar with boiling water at a ratio of 1 part agar to 1 part water. This should make a thick, gel-like paste. Once cooled, this paste should then be diluted again at a rate of 3 to 5 ounces of agar paste per gallon of water. The agar solution can then be applied to your lawn at a rate of about 1 to 2 gallons per 1,000 square feet. You can also use this mixture as a deterrent for insects, a soil softener, and a preventative measure against hydrophobic soil.

The agar mixture is my second favorite DIY wetting agent as agar powder is available in bulk at a local specialty foods market. While a solid option, agar and other seaweed powders can be difficult to find.

Why I Don’t Recommend Dish Soap as a Lawn Wetting Agent

Dish soap is a common recommendation for a simple, “homemade” wetting agent. However, in the concentrations that are needed to get the right amount of surfactant out of these products for them to work as a wetting agent, you’re also getting a detergent that could potentially weaken or kill your lawn. The reason dishwashing detergents are often recommended is that they contain SLS or SLES. If you’re going this route, it’s better to get these substances on their own or in a vehicle like baby shampoo, something with few additives.

The Wetting Agent I Rely on Most

When it comes to lawn care, I like to make the most of my natural resources and combine as many tasks as I can, as long as I’m still getting strong results. Why spend more time and effort than you have to? With this in mind, I prefer to create a strong compost/manure tea and add the recommended amount of SLS to that mix. I’ll then feed that mixture into a lawn sprayer with a tank and coat the lawn at a rate of about 5 gallons per 1,000 square feet. You can also use a spray bottle to apply the mix directly to problem areas or any hydrophobic spots to help prevent the issue.