Thatch is a serious problem in a lawn. Thatch is a layer of dead grass stems, grass roots and decaying grass blades that builds up on an unhealthy lawn. Grass roots will grow up into this layer and form an impenetrable barrier that will slowly starve your soil of water and nutrients. Thatch control tools are both preventative and curative in nature.
Assorted rakes keep thatch under control in your lawn. Just after mowing, use a leaf rake to spread grass clippings over a lawn and prevent a buildup of the clippings that lead to thatch. Use a thatching rake, which resembles a bank of knives at the end of a pole, to break up the thatch in a small lawn.
In a large lawn, a vertical mower can be used to break up the layer of thatch. The vertical mower is also known as a power rake. Power rakes resemble lawnmowers in that a set of motor-powered blades is enclosed in a decking and you push the motorized assembly before you. Inside a power rake, steel blades turn vertically around a central bar to slice through thatch. A vertical mower may remove as much as 80 bushels of thatch from an average sized lawn.
According to the University of Ohio, research shows that core aeration is the best control for thatch. An aerator punches or removes thatch and soil in tiny holes acaross your entire lawn. This allows water and nutrients to penetrate into the soil through the holes. If soil remains aerated, the grass roots grow down into the soil instead of up into the thatch, which both controls and prevents thatch buildup. For small areas, use a spreading fork or a pair of spiked aerator shoes to punch holes deep into the lawn. On small lawns use a sod-coring tool. Sod-coring tools remove sod rather than simply pushing aside the soil. For larger lawns, use a core aerator machine. This machine is a power tool that removes up to 60 tiny cores of soil per square foot.