Thatch and dethatch

Thatch is living material that is part of the growth of bluegrass in lawns.  An amount of thatch is normal in a lawn.  In the photo above, my finger is pressed down on the thatch layer that is growing over the top of the soil.  If soil is compacted or if the natural process of the lawn to consume thatch is compromised excessive thatch may build up.  If excessive that builds up, up to 1/2 or 3/4 inch or more, the best solution is to core aerate the area that has excessive thatch.  Regularly dethatching a lawn each spring usually is not necessary and will lead to other issues like increased summer annual weeds and will force the lawn to repair itself in the spring instead of tillering and building density.  Follow this link to UMASS on thatch management.