What is THATCH? The term "THATCH" is a well-known term to professional turfgrass people such as golf superintendents, other greenskeepers, stadium managers and sod growers. However it's still a relatively new tem to most homeowners. The image that comes to mind immediately, of course, is that of thatched roofs, still very common in many parts of the world. When straw, reeds or elongated leaves are arranged in thick layers running parallel to the slope of a roof they can be very effective in keeping out the rain. Unfortunately much the same condition can develop at the base of the grass plants on your lawn. When it does, the condition is simply referred to as " thatch". Here's how thatch develops and the problems it can cause. A healthy, well-fertilized lawn usually produces an excessive amount of leaf growth. Some of these leaves have a tendency to grow outward almost parallel to the ground and others get trampled into that position. As these leaves or blades of grass get thicker and grass clippings or other debris are added, this layer of thatch gets deeper and deeper. Your lawn is robbed of air, moisture and food. As the thatch gets deeper and more dense very little air, water and nutrients get to the roots of your grass plants. Roots are inclined to stay close to the surface and some grass plants will die because of a lack of water and food. This in turn adds more thatch. You get minimum benefits from rainfall, lawn sprinklers or applications of fertilizer. Water is inclined to lie on the surface and evaporate or run off sloping areas without penetrating the soil. If there is a period of drought your lawn will be severely damaged. Likewise, any application of fertilizer is inclined to lie on the surface of the thatch, providing little or no nutrition for the weakened grass plants. This is how you get rid of thatch. Your regular lawn mower simply cuts the tops of the upright grass plants and does not remove any of the grass that lies horizontally on or near the ground. For this you require a machine with blades cutting vertically. When removing thatch it is best to cut parallel swaths across the area in one direction and then repeat the procedure with swaths at 90% to the first cutting (only if necessary). Do not set the blades too deep. They should just remove the thatch and not the soil.Your Rental company will have preset the blades for most lawns. When to remove thatch. You can remove some thatch from your lawn at virtually any time of the year if you set the blades at a very shallow cutting depth for minimum disturbance of the soil. Generally it is best to remove thatch in the spring and in the fall to avoid disturbing the grass plants in the hot dry summer weather. Thatch material makes good compost. The thatch material brought to the surface by the vertical cutting makes excellent composting material. Once properly composted this material can be used for mulching or added to your garden soil.