Last Updated on August 29, 2023 by ILGM Ninjas
Thatch, that grossly misunderstood part of your lawn that causes so many issues that is supposed to be there but not really, let’s dig in. Thatch simply defined is the dead root growth of the lawn. It is normal to have in a bluegrass lawn but is often overgrown (anything over 1/2″), meaning too thick which causes a lot of issues. The fundamental reason for this is a dead, inorganic failing soil devoid of microbial life. In a healthy lawn this would be continuously be broken down into humus and then topsoil feeding the lifecycles in the soil supporting the soil food web which in turn feeds the plants growing in them. Normally this serves to protect the roots and soil from extreme cold and heat and to preserve moisture near the surface. When there is no mechanism to digest this material, primarily from the use of synthetic fertilizers, the thatch begins to accumulate preventing air (specifically oxygen, a major catalyst of macro and micro nutrients) water and nutrients from getting to the roots efficiently. With the cost of water this alone should be a primary concern. When you combine a lawn that goes anaerobic with stagnant water that is trapped in the sponge-like thatch along with an inorganic soil that is high pH and then you can inhibit copper uptake in the soil, which is a natural anti-pathogenic metal and you can trigger a real eye sore like necrotic ring disease which probably popped up in your lawn if this formula probably about six weeks ago. Typically this would be met with an array of different “solutions” such as power raking (highly stressful on the lawn), core aeration, maybe some seeding and a possible rouge fungicide application, all of which provide some temporary relief for a season or two until the lawn gets backed up again. The real solution is to avoid synthetic product use, apply organic material, reintroduce biology and watch the thatch get digested back into the lawn feeding the microbiology, opening up the soil and starting the cycles which bring life to the soil and the plant growing in it. This is the proper way to manage thatch. No machines required, just biology!