We get this question more than any other question this time of year. While power raking has it's purpose, there are definitely times when you really don’t need it. Power raking is the process of mechanically removing excessive thatch from the thatch layer above the soil. Thatch is basically a layer of dead and living grass shoots, stems and roots between the grass blades and the soil. Aerating, de-thatching and power raking are all used to help control or eliminate thatch build-up in our lawns.
But before we start going to war on thatch, we need to know a couple of the biggest misconceptions about thatch that many of us have come to believe.
-Thatch is bad for the lawn- Thatch actually is not bad for our lawns. Almost all lawns have thatch and having some thatch in your lawn is beneficial to your turfs health. We have been taught that if there is thatch in your lawn, it needs to be removed. However, a healthy thatch layer, usually anything ½ inch or less, helps protect our lawn as an insulation from temperature fluctuations, helps retain soil moisture, helps prevent compaction by acting as a cushion, and also provides a constant source of organic matter to our soil as it continues to break down
–If you mulch your lawn, you need to power rake- This one is another big misconception. Proper mulching does not create thatch! Grass clippings are over 80% water. So grass clippings decompose very, very quickly. Remember, as mentioned above, thatch is made up primarily by dead and living shoots, roots and stems….not clippings. Now, if you mulch improperly, there is a possibility that the amount of clippings produced may take longer to decompose due to the excessive volume of the cut grass. In those instances, if the lawn is repeatedly mulched improperly, the clippings could possibly contribute to an increase in thatch
The reason this is important to know, especially if you are trying to decide if you should power rake or not, is we really don’t want to remove all of our thatch. An easy way to tell if you need to power rake your lawn, is taking a cross section or a plug out of the lawn and actually looking at the thatch layer as shown above. If there is more than ½ or ¾ inch of thatch, you may need to address it. But normally, that just isn’t the case. In the early spring, it can be deceiving when we look at our grass. Basically all we see is dead, brown grass. So we immediately assume we have a thatch problem, when all we really are seeing is the dead shoot growth from the preceding season. Once you mow your lawn down, you will usually eliminate the majority of that dead layer, exposing new, green growth below and leaving the beneficial thatch.
There are a few things that you can do to help maintain a good, healthy thatch layer in your lawn.
1. One of the biggest contributors to thatch buildup is based on your variety of grass. Kentucky bluegrass, zoysia, and sometimes bermuda will develop excessive thatch due to the amount of rhizomes or stolons produced by these varieties. Stem nodes, crowns and roots are more resistant to decay, therefore, they take much longer to breakdown and can build thatch up faster than other varieties of grass. Tall fescue, however, will rarely have an issue with excessive thatch unless the fescue has been over fertilized, over watered, or improperly mowed.
2. Proper fertilizing is another way you can help eliminate the accumulation of thatch in your lawn. Avoid over fertilizing, as excessive nitrogen will cause increased leaf, root, and stem growth. Over application of nitrogen will also acidify your soil, which can also reduce the rate of microbial activity in your soil, slowing down the rate in which thatch can be broken down. So, do not apply high rates of nitrogen in the spring or summer, to help eliminate excessive growth patterns in your cool season turf.
3. Lastly, maybe the most beneficial and important practices in maintaining a healthy layer of thatch, is core aeration. Without going too deep into the importance of aeration, just know that aeration helps to eliminate compaction in the soil, improving air movement and gas exchange into the soil, which in turn increases microbial activity, which then increases the breakdown of thatch. This is why you will rarely see thatch problems in lawns with earth worm activity. Earth worms naturally aerate your soil below the surface. Also, the cores pulled from the soil during aeration will remove a little bit of thatch as well.
Hopefully this helps clear up some of the confusion in regards to power raking or not power raking your lawn. We are not against power raking, and when it is necessary, it can definitely benefit your lawn, but make sure you analyze your lawn properly, or contact a professional lawn care company to go over it with you! If you decide that your lawn does indeed need to be power raked, make sure that it is done at the proper time of year. When needed, cool season turf should be power raked in the early fall, but it can also be done in the early spring if absolutely necessary. Warm season turf can be power raked in late spring or early fall, but the same rule applies, ½ inch of thatch is healthy for warm season turf as well.
As always, if you have any questions regarding your lawn, contact us or your professional lawn care provider, and we would be more than happy to help you with the proper solution to your lawn care problems! Thank you all and God Bless!!