Thatch is that bed of dead grass, brown roots, clipped stems, and lawn trimmings that builds up in your yard over time. A thin layer of thatch, less than half an inch thick, is ideal for holding in moisture and insulating the grass roots. When your lawn's thatch layer gets thicker than an inch or two, however, it's time to take action. You'll need to remove the excess buildup in a process known as dethatching your lawn— a lawn care activity that's best done in the springtime.
Recognize Excessive Thatch
The tightly woven layer of living and dead grass right under the tall grass blades is the thatch. When the thatch layer gets too thick, it blocks sunlight from the lower half of the grass blades, and you'll see them beginning to brown. You may notice your grass developing disease due to the thick thatch holding too much moisture. Heavy thatch can also contribute to nutrient deficits, shallow-rooted grass, and uneven or patchy lawn length.
Use a Rake to Dethatch
If you have a fairly small yard, or if your thatch layer isn't even an inch thick, you can probably get away with just raking it up. Using a rake is less traumatic for your lawn than using motorized equipment. Experiment with a regular rake first, and if that doesn't work well enough to draw out the thatch, invest in a special dethatching rake with extra-sharp tines. Those tines can get deeper into the thatch and lift it free.
Do a Post-Aeration Soil Cleanse
When you aerate your lawn in the spring, you'll see bits of earth that the fork or aerator brought up from deep in the soil. Those lumps of soil contain microorganisms that devour and digest the thatch from your lawn. To them, it's a tasty, nutritious snack; while to you, it's just in the way of your picture-perfect lawn. Resist the urge to rake or remove that extra loose earth right away. Leave it there until the next time you mow your lawn, and let the tiny organisms do some of the dethatching work for you.
In cases of extremely heavy thatch or large lawns, you'll need to rent special equipment. Motorized dethatchers are often called verticutters, power rakes, or vertical cutters. Their wire tines or vertical blades cut into thatch and drag it upward, out of the grass bed. You'll need to ensure that the type of verticutter you rent is designed for the type of grass you have. Consult with the experts at Kurtz Bros., Inc. or talk to the rental facility to ensure that you have the right cutter with the correct blade spacing and cutting depth. Before using the equipment, mark any septic, irrigation, or utility lines in your yard with small flags.
Reuse the Thatch
Maintain Your Lawn After Dethatching
After dethatching your lawn, you'll notice that the grass looks wrecked and torn up, especially in certain areas where the thatch was deepest. That's okay! Just give it extra care by watering heavily, applying some fertilizer, and sprinkling grass seed on any bare spots. You may also need to add some extra soil in places.