You’ve finally decided to take action to fix your lawn this year. But you’re wondering if it needs dethatching. What is thatch anyway, and is it a problem?
Thatch is the build-up of old grass roots and organic debris where the grass stems meet the soil. The photo below shows a layer of thatch measuring just over 1 inch. (Image adapted from the University of Maryland Extension ). Healthy lawns can have a thin layer of thatch (less than ½” thick) and still thrive. However, excess thatch gets in the way of water and nutrients reaching the soil and feeding the roots.

How do you know if you have too much thatch? To measure the thickness, first, find the brown layer just bel...