Dethatching involves cutting into your lawn with rotating blades or tines in order to remove excess thatch. While the process is absolutely necessary in order to ensure that your grass receives the air, nutrients, and moisture that it needs, it tends to be traumatic. It exposes grassroots, damages grass blades, and leaves your lawn looking ragged.

The reason for dethatching is so water, oxygen, and nutrients can penetrate the roots, so it makes sense to fertilize after detaching. Fertilizing after dethatching is advisable because it gives it ensures that the existing grass gets enough nutrients to accelerate its growth while also giving any new seeds the best odds of germinating and developing strong and healthy roots.

Here are some of the things that you should know about dethatching and why it is an important lawn maintenance routine.

fertilizing lawn after dethatching

You should dethatch your lawn as soon as its thatch layer becomes more than an inch thick. At this point, the thatch layer is usually so thick to a point where it becomes detrimental to the well-being of your lawn. A thick thatch layer will keep nutrients from reaching the grass’s roots, it will make it harder for them to breathe, and it can also harbor harmful pests and diseases. Therefore, dethatching your lawn as soon as it starts becoming problematic — which typically happens after every 5 years — is always advisable.

As far as the season for dethatching is concerned, the best period is one that gives the grass the best chance of recovering. Ideally, you should dethatch right before the grass enters its rapid growth phase.

If you have warm-season grass on your lawn, the ideal period will fall either in early summer or late spring. However, if what you have is cool-season grass, then the best time to dethatch will be in late summer or during early fall.

As far as fertilization is concerned, it should be done right after dethatching. Doing so immediately after is important because of two reasons. The first is that it will provide the grass all the nutrients that it needs in order to recover at a faster rate. The second reason has to do with the fact that dethatching will make it easier for the fertilizer to reach the soil and hence giving it a better chance of reaching the soil and the roots of your grass.

Should I seed after dethatching?

seeding lawn after dethatching

Yes, you should seed after dethatching. This is because dethatching tends to leave a lawn looking ragged with patches of bare spots. Seeding helps to cover these spots with grass, something that then helps to speed up the rate at which your lawn recovers its initial aesthetic appeal.

Seeding after dethatching is also recommended because thick thatch layers tend to keep seeds from getting in contact with the soil. As a result, they diminish the chances of seeds developing deeper roots, getting access to nutrients and water, and blossoming into thick, strong, and green blades of grass. Since dethatching helps to clear the way for seeds, seeding after dethatching improves your chances of getting a healthy and aesthetically appealing lawn.

How to dethatch and fertilize my lawn

While dethatching a lawn is a simple and straightforward process, there are a few guidelines that you should stick to if you want great results. Here are the steps that you should follow if you want to end up with a healthy and aesthetically pleasing lawn.

Step 1

Cut the grass to its lowest recommended level. While the ideal level varies depending on the type of grass, mowing it until it is at least half its normal size will do. And after you are done, collect the grass clippings and dispose of them.

Step 2

With your lawn at an ideal height for thatching, the next step is to water the lawn. Do not overwater the lawn. Light watering is recommended as it will soften your lawn, making it easier for the dethatching tool to cut through the thatch. And since overwatering the lawn or working on it while it is still soppy wet will lead to the dethatching tool pulling soil and roots during the dethatching process, leaving the lawn for at least a day before working on it is recommended.

Step 3

The next day, when the soil is still moist, you should then start to dethatch it. Simply set the dethatcher height to the recommended height — it is better to an error on setting it higher than setting it too low — and then go over the lawn removing excess thatch. You may have to give various spots a few passes before you remove the right amount of thatch, and in such cases, it is always advisable that you take the subsequent passes at a right angle to the initial pass.

Step 4

After you have removed the desired amount of thatch, you should then rake your lawn. Use a regular rake to remove the loosened thatch and other debris. Collect it in a pile, and then dump it in your composting site.

Step 5

With your lawn freed from the resulting debris, it is now ready for fertilization. Simply apply a fertilizer that isn’t nitrogen-rich or at least one that uses a slow-release formula. And after you are done, water your lawn.

FAQ's

No, you shouldn’t fertilize after dethatching. This is because, before dethatching, the lawn will have a thick thatch layer. This layer will keep the fertilizer from reaching the soil. It will also keep it from getting absorbed by the roots of your grass.

There is also the fact that you will have to remove the excess thatch through raking. And since most of the fertilizer will definitely be deposited in the thatch, you will be essentially removing a significant chunk of the fertilizer when you eventually get rid of the thatch layer. In short, fertilizing your lawn before dethatching will amount to you wasting your fertilizer.

Yes, you can fertilize and overseed right after dethatching. In fact, it is recommended that you do so because it will give your lawn a better chance of recovering at a faster rate.

Fertilization ensures that any existing grass that remaining grass has all the nutrients that it needs to rebuild itself into stronger and greener grass. As for overseeding, it is necessary in order to get rid of the ragged and patchy look that is common in dethatched lawns. It simply provides extra grass to cover any bare patches on your lawn hence guaranteeing a more wholesome and appealing look.

Fertilizing and overseeding your lawn after dethatching, as opposed to before dethatching, is important because it improves the effectiveness of these lawn care activities. This is because the dethatching process eliminates the blocking effect of thick thatch layers, something that then makes it easier for seeds to get in contact with the soil, and for fertilizer and nutrients to reach the roots of the grass.

No, you cannot dethatch your lawn with a normal rake. This is because normal rakes do not have deep-enough tines or blades that have been optimized to cut through thick thatch layers.

Trying to use a normal rake to dethatch a lawn is an extremely ineffective, slow, and labor-intensive option that is almost impractical especially when you are dealing with either thick thatch layers or medium-sized lawns. This is so especially when you can easily get your hands on a dethatching rake, power rakes, and vertical mowers by renting them from a local store.

While dethatching is essential to the survival of your lawn, it is important to remember that thatch serves a purpose. Thatch helps to regulate soil temperature, limits the rate at which moisture evaporates from your lawn, and gives the lawn cushioning against physical trauma. Therefore, you should only dethatch your lawn if the thatch layer has grown so thick to a point where it is affecting the health of your lawn. Otherwise, for as long as the thatch is under ½ inch thick, you should leave it alone.

Timothy Munene
Author: Timothy Munene - Timothy is a freelance writer and an online entrepreneur.