There are a lot of simple habits you can undertake to help your lawn look great. They often cost very little aside from time and energy, and are fairly straigtforward to accomplish. Dethatching is a great example of a once or twice a season activity that's often overlooked. In fact, our research found that about 95% of people have no plans to dethatch this year. But dethatching is the most important overlooked practice in lawn care, and has a huge impact to the overall health of your lawn heading into fall.
If you have a cool season lawn (fescues, rye, and bluegrass) late August to early September is the best time to dethatch. The daytime temps are usually cool enough by this time to allow a quick recovery. As you can imagine, dethatching will stress your lawn, so you'll want to avoid this activity over the hottest time of summer when the lawn is usually under peak stress.
For warm season lawns (bermuda, zoysia, bahia, st. augustine, and centipede) you'll want to dethatch in June. Essentially, the best time to dethatch your lawn, regardless of where you live, is just before your lawn enters a high-growth period.
What is thatch?
Thatch is a tangle of dead grass, dead roots, and decaying matter that builds up at the base of your lawn, directly above the soil.
Detatching is simply the process of removing some of the dead organic material from the top of your soil. If your lawn is more than 2 years old and you don't know when it was last dethached, plan to do it at least once this year, and every other year going forward.
Why is thatch bad for your lawn?
Some thatch breaks down over time, but it usually accumulates faster than it breaks down, and creates a spongy barrier between your soil and the air. This ‘sponge’ builds up and leads to issues over time…
- Thatch heats up your lawn. All of that dead material traps heat and acts like insulation. It’s like wearing a blanket in the heat of the summer, causing soil temperatures to rise. If your soil temps rise too high, your grass will go dormant to protect itself from the heat.
- A thick layer of thatch doesn’t allow water or fertilizer to get down into the soil. If you have a heavy thatch layer, a lot of the water and fertilizer you’re applying to the lawn is directly absorbed by the thatch layer, and only a small amount gets to the root zone where the grass system can use it. In other words, if you have a heavy thatch layer on your lawn, you’re effectively choking off your lawn and wasting the money you spend on lawn care products and irrigation.
- Thatch makes your lawn more prone to disease. Turf grasses need air circulation to prevent fungus and disease. This is especially important as air temps and dew points rise in the summer months. If your thatch layer is preventing air circulation, your lawn will retain moisture - a recipe for disease once the summer hits.
- Color is impacted. If your lawn is filled with compacted brown spongy material, you'll notice the color starts to fade, and your grass itself will thin out and not respond as well to fertilizer. So even if you use a quick release fertilizer, it’s not going to get that pop of dark green you’ll get on healthy turf.
How to Dethatch:
You'll need to get a thatch rake, which can be easily found at a hardware store or on amazon. Just makes sure you get one with metal tines like this one. Or if your lawn is larger in size, you may want to opt for something automatic like this one from Greenworks.
Mow your lawn a little shorter than usual and bag the clippings. This will make it easier to rake.
Rake the lawn using your thatch rake. The grass should be dry before beginning this step. You should feel the tines digging in and you'll probably pull a good amount out material of the lawn. It may feel like you're damaging the lawn, but the thatch layer often binds together and is difficult to pull up. Bonus - this will be a great workout if you opt for the standard (non-automatic) rake!
Once you've finished raking (or you've had enough) you'll need to get all the thatch off your lawn. You can rake it off the lawn, use a leaf blower, or just run your lawnmower and bag the clippings. When you're finished, your lawn should look like this:
Again, there's no need to be concerned, and you're not damaging the lawn. You're just getting up all of the dead material that has been choking your lawn and preventing water and nutrients from getting into the root zone.
Finish with a slow release application of liquid fertilizer. Your lawn will look a little ragged for a week or two, but will bounce back with the help of a slow release fertilizer. Pick up a drought pack to help your lawn recover.
Finally your lawn can breathe a little easier, and will be in great shape for cooler weather this fall!