Does my lawn need Thatch Control?
Control measures should be based on an actual thatch problem--not just done routinely. Determine the need for thatch control by cutting a small pie-shaped, cross-section in the turf, lifting it, and examining the extent of thatch build-up. If the depth exceeds 1/2 inch, take steps to reduce it and prevent further accumulation.

What can I do to Control Lawn Thatch?
There are a couple options. You can control thatch through lawn aeration (?) or by using a vertical mower, sometimes referred to as a power rake.

Aerification or vertical mowing is also an excellent way of preparing an old or damaged lawn for seeding (applying grass seed into the existing grass). Soil at the surface during seeding greatly improves germination of overseeded grasses.