Lawn Thatch Prevention: Practical Ways to Avoid Thatch Problems
Posted On August 6, 2021
Thatch is a layer of dead grass roots and stalks found between green, growing grass and the ground. A thin layer of straw (less than 1/2 inch deep) is important for the health of the lawn. A thin layer of straw protects the lawn from extreme heat or cold and provides cushioning to prevent soil compaction in high traffic areas.
Soil compaction prevents oxygen and nitrogen from entering the soil. These gases promote root growth and contribute to the proper mix of nutrients in the soil. Good soil is one of the most important factors for a healthy lawn, so preventing soil compaction is definitely a good thing.
When the straw becomes thicker than 1/2 inch, a lot of problems can occur. The straw acts like a sponge, absorbing moisture, but unfortunately, it dries quickly. It contains few nutrients. Once the straw becomes too thick, the roots of the grass can start to grow in it and never reach the ground. Since straw is low in nutrients, this is a recipe for a lawn mess.
Thatch also creates stress on lawns in drought conditions. The straw absorbs most of the water, the water evaporates and little water reaches the ground. If there is no water in the soil, your grass won’t get the soaking it needs to recover from a drought. Other straw problems include harboring harmful insects and bacteria.
Causes of straw
Thatch can be caused by multiple factors. First, be aware that certain types of lawns are prone to thatch and therefore may require more extreme prevention measures. These types of grass include: Bermudagrass, St. Augustine grass, Zoysiagrass, Bluegrass, and Red Fescue.
In addition to the type of lawn, excessive soil compaction produces straw because the roots of the lawn cannot penetrate the soil. The roots grow and die on top of the ground, creating straw.
Another cause is infrequent cutting. Mulched lawn mowers cut grass and leave grass clippings on the lawn. These clippings are usually an excellent lawn fertilizer. However, if the cutting is not frequent enough, the cuts will be long and in large groups. The groups kill the grass underneath, creating straw.
Lastly, excess fertilizer and watering can lead to overgrowth of the grass. There may not be enough nutrients to support the overgrowth, so more grass stalks will die and create straw.
There are a variety of things that can be done to prevent thatching. First, it is important to water and fertilize an adequate amount, but not too much. One inch of rain / irrigation per week is a good rule of thumb. Follow the recommendations for the fertilizer you are using to avoid overfertilizing.
Second, keep the soil pH above 5.5. PH less than 5.5 is too acidic for a healthy lawn.
Another important consideration is mowing your lawn often enough and allowing grass clippings to fertilize your lawn. Mowing the lawn is often important, as the clippings will be small to drop between the grass stalks and it will be possible to obey the one-third rule of mowing the grass. That is, cut 1/3 the height of the grass each time the grass is mowed.
However, this must also consider the type of grass and its optimal cutting height. A common myth is that grass should always be cut to 3 inches or more. All common U.S. grasses, except St. Augustine, have an optimal cutting height of less than three inches. Some St. Augustine varieties can be cut to as little as 2 1/2 inches. Some common grasses, such as Bermudagrass, Centipedegrass, and Zoysiagrass, need to be cut to a height of one inch.
Perhaps your straw problem has already gone too far. The standard way to remove thatch is to aerate the lawn with a tool that drills holes 1 to 6 inches deep and 3/4 inch wide in the soil. The tool removes the plugs of dirt / straw and they are left to decompose in the grass. Nutrients from the vents contribute to the decomposition of the straw. Another method is the power rake. If the thatch in your lawn is more than 1 1/2 “thick, this is a bad situation. You will need to replace the grass with seeds or grass. That is, tear everything up and start over.
Robotic lawnmowers are mulch mowers that cut themselves without human intervention. Consider purchasing a robotic lawnmower, as it is much easier to obey the 1/3 rule of mowing and mowing often enough to avoid thatch build-up. In addition, you will have more time available to aerate.
your lawn and perform other maintenance tasks. Your lawn will be much greener and healthier.
Gail Jones is a writer and home automation product expert. He works for Paradise Robotics, a Chicago-area company that specializes in life-enhancing products. You can reach Gail at [email protected]