Lawn Dethatching Guide: How and When to Dethatch Your Lawn

Dethatching a lawn is not a necessity. But when done properly, lawn dethatching can really increase the quality and health of your lawn.

Many people have issues with their lawn, and are not even sure of what thatch is and how it affects the health of a lawn. Thatch is an organic layer of debris usually made of dead and alive plant material. This usually forms where stems meet the roots at the soil. This can build up and turn into a thatch layer. In small amounts this is good for your lawn, but when over 1 inch, it can cause major issues. It is definitely something to worry about and take care of regularly.

Why Should I Dethatch My Lawn?

Thin layers of thatch allow water, nutrients and air to penetrate into the soil and reach the roots of your lawn. But too much thatch can do quite the opposite.

With thatch thicker than 1 inch, your turf will become a haven for insects and other pests. Lawn diseases also thrive in thick thatch.

If you want a healthy and beautiful lawn, you will want to dethatch anytime your thatch is thicker than .75 inch. You can check this by taking a small garden trowel or a spade and digging up a section of your lawn. Check the turf cross-section (you can replace it when you’re done).

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When Should I Dethatch My Lawn?

There are certain times when you should specifically dethatch your lawn. First make sure to always check the thatch layer and make sure it is more than 1 inch in order to dethatch.

Then make sure you are dethatching in the season according to what grass you are growing, and should coincide with the major growth times. For Kentucky bluegrass, or other cool season grasses, the early fall or late summer is the best time to dethatch. For Zoysia grass or other warm season grasses, early summer is the best time to dethatch.

The wrong time to dethatch a lawn is when your grass is stressed as this will cause major damage.

How Often Should I Dethatch My Lawn?

There really isn’t a right about of times you should dethatch your lawn. You should dethatch your lawn specifically whenever it becomes unhealthy to your lawn. This means generally around as thick as 1 inch of thatch.

How to Detatch Your Lawn (Different Methods)

There are a variety of methods to dethatch your lawn.

First you can simply hire a professional. This is recommended if you have excessive thatch, are short on time, or you simply hate working in your yard.

If you don’t mind a little sweat, there are plenty of DIY dethatching techniques. These are mainly manual or with the use of power tools.

The best way to decide if you would like to use a dethatching rake or a power tool is evaluating the size of the area, as well as how good of physical shape you are in.

Tools Used to Dethatch Your Lawn

If you decide to dethatch your lawn yourself, there are three main ways: Manual rakes, power rakes and vertical mowers.

There are both positives and negatives to every dethatching tool and technique, so I’ll discuss those here, and share how I dethatch my lawn.

Manual Lawn Deathatching

Manual dethatching is the most physically strenuous type of dethatching. This is done with a rake that has curved blades, and digs into your lawn as you dethatch.

If you’re going to dethatch your lawn with a rake, invest in a dethatching rake (I own this one available on Amazon, and it works well). There are specific rakes for manual dethatching which are usually best when you do not have an incredible amount to dethatch. This is best for small lawn areas and these rakes are sold at most lawn & garden stores.

You could try to use that iron rake you already own, but it won’t work as well. It’s worth buying one specifically designed for dethatching.

If you are not in great physical shape then this will most likely not be the best option for you unless you only have a very small area to cover. This would be the cheapest of the options to purchase.

Dethatching with a Power Rake

Power rakes are similar to walk-behind lawn mowers and have rotating tines that slice into the grass/turf. These tines dig into the thatch and go all the way into the soil to pull pieces up and loosen/rake your lawn thatch, bringing it to the surface of your lawn.

These power rakes are mainly good for thin layers of thatch. Power rakes are not a great option for sensitive or young grass. You would want to use this on strong grass that you aren’t worried to rip out, and I usually recommend overseeding afterward.

Most people who use a power rake will rent a professional one from their local hardward store or box store. But you can purchase one if you know you’ll be dethatching your lawn pretty regularly.

My Lawn Dethatcher Setup

I personally own this Greenworks Dethatcher, and it works really well. I don’t like that it’s corded, but I own a Dewalt portable power station, so when it’s time to dethatch my yard I just strap that on top, and plug the Greenworks power rake right into that which makes it cord-free, running on my Dewalt batteries.

I’m really happy with this set-up, but I wouldn’t recommend the Greenworks Dethatcher to someone with a large yard who doesn’t have a battery-powered generator setup like mine. Dragging a cord around a big yard can be frustrating.

If you have a small yard, the Greenworks tool is a great value and a better option than renting. It was an easy choice to top my list of the best lawn dethatchers, which actually includes a few cordless and tow-behind models that are better for large yards.

For weekend warriors who plan to dethatch their lawn once every 3 years or so, I don’t recommend purchasing a power rake. Rent one when you need it and save the space in your garage for something else.

Dethatching with a Vertical Mower

Being the strongest of the three DIY methods, vertical mowers slice through thatch layers and into the soil. These tools are similar to power rakes, but are much more powerful. Use a vertical mowers for thick thatch and lawns that need major work.

These tools actually dig into the grass roots, but you have control of how much is removed at once. Vertical mowers can be rented at most hardware and box stores (in fact, they’re probably what most of these stores rent), and would be the most expensive option.

When I rented a commercial dethatcher, I’d talk to my neighbors and split the cost so we could all do our yards at the same time. It’s a good way to save some money and green up the entire neighborhood.

Lawn Maintenance After Dethatching

After dethatching your lawn your work isn’t over.

You will have a somewhat patchy, thin and slightly unhealthy looking lawn. It is quite important to get your lawn back to looking beautiful in all its green glory. After dethatching, plan to overseed your lawn. Pick a good quality seed and consider adding a professional grade fertilizer.

It is also important to continue to test your lawn every 2-4 years. For most lawns, dethatching every third year will be sufficient.

There are also a few things to add to your lawn. First you will need to make sure to test the pH of the soil (you will want it between 5.8-7.2, amending with lime if needed).

Also plan to keep it nutrient rich. Your lawn may not return to normal immediately, but just continue to nourish it and water it properly. One good way to keep the pH in proper form is to add ground limestone rock (commonly known as “lime”).

Limestone rock naturally contains calcium carbonate and magnesium carbonate. These both work to make the soil less acidic. Even though these are considered essential nutrients, you should continue to use fertilizer as well. If you check on your lawn and continue to follow these steps your lawn should continue to thrive for years to come until the next time you will have to dethatch.

Lawn Dethatching Step-by-Step

Here is the step-by-step process I follow when I dethatch my lawn.

1. Mow the grass shorter than usual – about 2 inches.
2. Dethatch the entire lawn.
3. Rake up all of the loosened thatch and dead grass, add to my compost pile or bring to my local brush dump for composting.
4. Add starter fertililzer (I use this one).
5. Overseed with a good blended sun and shade seed (I use one without fillers, bought from my local nursery so I know it will thrive in my area).
6. Rake in seed lightly with the back of my leaf rake to get good soil contact across entire lawn.
7. Top-dress lawn with 1/4″ of organic compost, raked lightly with back of leaf rake to spread evenly. I have compost available from my town brush dump for free, and that’s what I use if I don’t have enough in my own compost pile.
8. Water daily, mowing high when new grass gets to 3-3.5 inches.

This is a lot of work, but taking these steps every 3 years improves the soil, removes thatch, and thickens my lawn with new grass seed and for me it’s a very satisfying weekend project.

I enjoy the fruits of that labor for the next three years.

Final Thoughts and Tips on Lawn Dethatching

Lawn dethatching may seem like something you don’t have to do, but for most homeowners it is vitally important.

If you care about having a lawn full of healthy grass, free from disease and insects then dethatching is something to think about.

Dethatching can definitely be a DIY project for most homeowners. But, if you have neglected your lawn, and the thatch layer is over 2 inches thick, consider hiring a professional.

It’s a lot of work, and if you have the money, getting someone to dethatch and remove the dead grass will save you a lot of time and back strain.

You may need multiple sessions if you have an excessive buildup of thatch. And you must remember not to remove too much at once or you will disrupt the roots.

If you have a large thatch problem or feel unsure of what to do, your local lawn professional or garden center can help you make the right decision.

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