What Is Lawn Thatch?
Lawn thatch is the layer of grass clippings and other organic material (plants, roots, stems and leaves) that builds up between the ground and visible grass. This occurs when new grass grows faster than the dead grass clippings around it decompose, which blocks air, water and nutrients from penetrating grass roots. Fertilizer is wasted since it only feeds the top layer and not the roots, and water runs off instead of getting to the root systems. Thatch is not necessarily a problem; less than a 1/2 inch of thatch provides benefits for the lawn. Once thatch builds up to more than a 1/2 inch, however, it needs to be removed for the health of your lawn.
What Causes Excessive Thatch in a Lawn?
Excessive use of fungicides and nitrogen, frequent but shallow watering and heavy and compacted soil all contribute to thatch. Use fungicides and fertilizers in moderation, water deeply but less often and treat the soil before planting new lawns to help prevent thatch.
How Do You Prevent Lawn Thatch?
To prevent thatch, be thoughtful about what you add to your lawn and how you care for it. Avoid overusing fungicides, which will kill bacteria that help break down decomposing grass, or fertilizer, which can cause the grass to grow too quickly. Frequent but light watering can also cause thatch, so water deeply but less frequently.
Additionally, aerating the soil — creating holes and pulling out the plugs of dirt —once a year is an important step to keep the lawn healthy and avoid excessive thatch. Lastly, because poor soil can contribute to thatch, amend soil before planting a lawn.
What Will Break Down Thatch?
Thatch can be broken down manually with a thatch rake or mechanically with a machine-powered dethatcher. Thatch rakes are heavy-duty rakes meant for pulling up tough organic matter. Machine-powered dethatchers are free-standing machines that look like push lawn mowers, or attachments added to the back of a tractor. Both versions of mechanical dethatchers have metal teeth designed to pull up thatch.
Does Raking Remove Thatch?
Raking with a garden lawn rake can help prevent thatch by removing excessive clippings, leaves and other organic matter from the surface of the lawn. However, to remove thatch, use a thatch rake, which is heavier-duty than a garden rake. If there's a thick layer of thatch, a machine-powered dethatcher may be necessary.
Does Aeration Reduce Thatch?
Aeration helps loosen soil and reduce compaction, helping to alleviate and prevent thatch. Additionally, it opens holes to help water flow into the soil, which can be challenging with thatch. When done in conjunction with dethatching, aeration reduces thatch and improves the health of your lawn.
What Is the Best Way to Remove Thatch from a Lawn?
Spongy texture and brown spots are signs that you have excess thatch buildup. Use a hand- or machine-powered dethatcher to remove thatch.
Thatch is not necessarily bad. When thatch is less than 1/2 inch thick, it provides benefits like temperature control and extra cushion. However, if thatch is 1/2 inch thick or more, it becomes harmful to the lawn and needs to be removed. Dig out a small section of grass to see how thick the thatch is.
