How To Improve a Lawn Growing in Clay Soil

Clay soil can create problems in lawns. They are dense and compacted and have poor drainage. They stay soggy when wet, and turn rock hard when they dry out in the summer. When soils are this “tight” due to clay, the necessary air, water, and nutrients cannot move through the soil. Roots are stunted and the grass is stressed, weakened, and more prone to thatch, disease, insects and even weeds.

There’s no way around it: if you want your lawn to be healthy you must improve the clay soil.

If you were dealing with a garden bed instead of a lawn you could simply mix or deeply till in lots of organic matter such as compost, peat moss, leaves etc., and this would result in a much improved and more bio-active soil often within just a season or two.

When you are dealing with a lawn, there is no way to till in organic matter into and below the root zone without tilling up and destroying the lawn. The standard advice is to “top dress” the lawn with compost, leave the clippings from mowing, fertilize organically and wait…wait…wait for all of that organic matter to eventually decompose and improve the soil. But the denser the clay, the longer it will take for this to occur – often many years.

The reason it takes so long for clays to improve when top dressed as above is that the soil microbes necessary for decomposing organic matter are aerobic – meaning they need air/oxygen to survive. Clay, which is made up of microscopic-sized particles tightly bonded together, has very little air in it. A good garden topsoil has 20-25% air in it. A clay soil might have only 3-5% air in it, and most of that is near the surface instead of into and beyond the root zone. Even if you use liquefied organic matter for soil improvement, the lack of air in the clay soil slows down the improvement dramatically.

A Faster Solution for Improving Clay Soil

If you could increase the amount of air in the clay by just a small amount, while at the same time putting organic matter deeper into the soil, you would encourage the beneficial soil-building microbes to generate and grow in numbers. For this purpose we have developed a product called Aerify PLUSLiquid Soil Aerator and Bio-Activator. It is a combination product containing a strong soil penetrant and rich, concentrated organic matter.

Aerify PLUS breaks apart some of the clay bonds in the soil to create microscopic air space in the clay. Each application builds on previous ones. It also adds liquefied Seaweed and Humic Acids (Carbon) to help generate and feed beneficial soil microbes of all types (including mycorrhizae). It helps improve drainage in your lawn, provides trace elements, encourages deeper rooting, frees up nutrients and water in the root zone, and helps move organic matter deeper into the soil.

Additionally, once your clay soil begins to open up, the soil becomes healthier and earthworms will start to appear in your soil in greater numbers. Earthworms will enhance and speed up the soil improvement process because they aerate the soil as they tunnel up and down. They also digest thatch and other organic matter in the soil and convert it into humus and rich, fertile castings.

If your lawn is growing in a poor clay soil, it will always be prone to the problems that come with clay. Improve the clay and you will improve the lawn. It is as simple as that.

(FYI, I treated my own lawn organically for many years and top dressed with compost as well. Though the top 4-5 inches eventually started looking pretty good, the clay underneath remained gray and sticky. After a few seasons of treating with Aerify PLUS, it was as if all the organics that I had put in the soil were finally able to be utilized down deep where I wanted them to go. My clay soil became dark and crumbly more than 1½ feet deep – and earthworms abound.– S. Franklin, President)