What is thatch? It is a dense, brown, spongy, organic layer of both living and dead grass, roots, and stems accumulating above the soil surface in turf. When thatch exceeds more than one inch it becomes problematic. Because thatch is spongy and once wet stays wet; the opposite is also true, once dry stays dry without significant deep watering. It is a perfect breeding ground for insects, diseases and blockage.
When thatch builds up, it blocks water, air, and nutrients from reaching the grass root zone. A lawn with dense thatch dries out very quickly because the water is locked up in the thatch and not reaching to the soil and roots.
The picture below shows a lawn less than a year old with a very heavy thatch layer. The homeowner was watering twice a day and mowing the grass very short. Overwatering and watering frequently contributes to significant thatch buildup. When talking to customers and they bring up they have heavy thatch, my first diagnostic question is, “How often are you watering?” 9/10 times their answer is daily, twice a day – daily, or every other day but twice a day on their water day.
If you notice in the picture below the thatch layer is so dense and thick nutrients and water will be absorbed in the thatch layer which acts like a sponge and will not get down to the root zone. The thatch is damp and the soil underneath is dry as a bone even though the customer had watered that day.
The picture below is another example of how overwatering causes excessive thatch overgrowth. The homeowner said the lawn looks heat stressed right after mowing and dries out quickly so they add extra watering cycles. The thatch is very dense and it is no wonder water and nutrients are not penetrating down to the root zone! This is a vicious cycle.
I hope you understand frequent watering in Colorado contributes to excessive thatch buildup. Every lawn has thatch and it is normal. This post is about how to keep the thatch layer from getting too thick. There are some simple practices to keep thatch from getting too thick.
- Stop watering daily or twice a day – please. Utilize the Cycle and Soak Method to water smarter.
- Mow grass at highest height on mower setting. Tall is happy; short is crappy.
- In severe cases, power raking or detaching is needed to get the thatch layer under control.
- We offer a Liquid Dethatch application which uses biology, living micro-organisms, to digest the thatch and help keep it at a healthy level.
There are other factors which contribute to thatch buildup. Learn more here : https://pss.uvm.edu/ppp/articles/thatch.html