If you have to remove excess thatch from a lawn then you have roughly 5 main ways to get the job done. In this video I will explain the differences along with the pros and cons of using:
- A Thatch Rake
- An Electric Dethatcher/Scarifier
- A Gas Powered Dethatcher/Scarifier
- A Liquid Thatch Digester
- A Core Aerator
As you probably already know thatch layers that are less than half an inch thick are usually normal and healthy. Thatch in the quarter inch range for instance shades and insulates the soil from cold overnight temps and beating heat during a sunny mid-afternoon summer’s day.
Thin layers of thatch also retain moisture in the soil just like mulch holds moisture in the soil of a garden bed.
Additionally beneficial soil microbes and bugs call the thatch layer home and we wouldn’t want to take that away from them now would we?
If however the layer gets too thick it starts becoming a problem for decomposition of clippings, water & nutrient penetration, and oxygen flow. As a result once thatch gets too thick it starts impeding a lawn’s performance at an accelerating rate if not addressed.
Why You Might Want To Use A Thatch Rake
Thatch rakes are really awesome at getting tons of surface debris up off a lawn surface so that the thatch layer is more easily exposed. Sometimes collected clippings don’t break down as fast as normal because they are sitting on thatch instead of soil so removing them can be beneficial right when you begin the thatch removal process.
Thatch rakes are also the cheapest tool you can buy for thatch management and they can be used in some places that larger machines simply can’t reach.
If you have irregular paver stones or grass under a low tree or obstacle a thatch rake can usually reach what the machine can’t get to.
Unfortunately the thatch rake is an enormous amount of work to use on a large lawn space and even the most physically fit people around will struggle to use them for long periods of time continuously…and that’s why man made electric dethatchers and scarifiers.
An Electric Dethatcher or Scarifier Is The Best Option For Many People
These are great options for people that have rhizomatic or stoloniferous grass types but don’t have an excessive thatch layer. I would classify these machines as maintenance machines or power rakes because they do similar work to thatch rakes but without the need for your own physical effort.
Dethatchers typically have flexible tines that scrape the surface down to 1/8”-1/4” below grade. They will remove surface debris and loosen or score upper-most layers of thatch without really removing the actual fibrous thatch layer.
The benefit in this is that oxygen can flow more freely into a healthy thatch layer while water and nutrients may be able to get through it more efficiently and get into the soil where the root systems of our grass plants live.
Some dethatchers provide an interchangeable system where the dethatching tines can be swapped out for hard inflexible blades called scarifiers. These basically cut grooves in the thatch layer and are often used in slit-seeding projects. They can usually reliably cut a bit deeper into the soil but because they don’t scrape the debris removed is sometimes less than a dethatcher that scrapes the lawn surface and drags material along for the ride.
The majority of electric homeowner detahtchers/scarifiers are affordable for most people and they typically range between $100 and $250. Some machines cover wider paths, some dig deeper into the lawn surface, others provide more power to the yard owner.
They are all limited in power by the electric line however and for large lawn spaces they can be impossible to use because power outlets might not be reachable from the furthest sections of those lawns.
► See the following post for more: The Best Electric Dethatchers Compared & Reviewed
There are also a few battery powered options on the market these days that can get past the limitation of the corded leash but they are even less powerful that the corded options at least at this time. At time of writing I haven’t yet reviewed these options in depth.
For deep thatch layers measuring between 0.5” to 1” in depth these machines don’t scrape or cut deep enough to make a large difference in thatch but when used in tandem with other options like core aeration and/or liquid thatch digester products they can start to make a big difference.
As an alternative to using an electric or battery powered tool the larger gas-powered dethatchers and scarifiers are a great option to consider.
Are Commercial Grade Gas-Powered Dethatchers (Scarifiers) That Much Better?
As a rule of thumb these machines are a lot better than the common electric versions however they are very expensive, quite heavy, and hard to use. Even if you are up for the challenge most people won’t ever use them on their lawn more than 1-2 times per year so buying them doesn’t make sense for most people.
Because of this these machines are usually owned and operated by lawn and landscaping companies that will use them more often and can take on hired jobs for homeowners around their local service area.
You can usually find local equipment rental shops to rent these machines and use yourself but you’ll have to make sure you can safely transport the machines and use them efficiently.
Although they work better they still have additional limitations too. For instance most of these big machines still don’t scrape or cut lower than about 1/2”-3/4” below the lawn surface. If you have a particularly bad layer of thatch this might cut through it all the way but not for everybody. In my lawn alone I’ve found localized patches of thatch measuring a full inch thick so the big gas powered machines still won’t cut through it all without additional steps being taken.
For these reasons I find it advisable to take the gradual remediation approach and apply liquid products to the lawn that help in breaking down the thatch layer and returning it to the soil much like you would take a compost pile and turn it back into usable soil.
There Are Two Different Types of Liquid Thatch Remover – Don’t Confuse Them
These liquid products are all easy to spray on a lawn setting and even the most expensive of the products are usually much cheaper than buying electric equipment or paying a lawn care business to come and run a large scarifier over it.
When you consider cost this is the best route in my opinion but you’ll have to warm up to the fact that this will be an ongoing project for you for a couple of season most likely because thatch doesn’t break down overnight even when you apply thatch digesters to the lawn.
Of the liquid thatch removal products on the market the biological thatch digesters categorically add microbes and biological life to your lawn that will theoretically speed up the decomposition of the thatch layer. Unfortunately most lawns already have soil microbes in them that can do the same job but they are not active enough to get the job done efficiently.
Not only that but the biological thatch digesters are usually have a short shelf life and potentially all of the good stuff in the bottle may not be alive or active when you finally apply it to the lawn. It’s like buying a bucket or worms or crickets; some of them (or all of them) may be dead in the package when you bring it home from the store.
The better alternative is to apply liquid thatch removal products that don’t actually add to the soil biology of your lawn but feed it instead. The products that are designed to feed the microbes in your soil and improve the soil over time will usually result in the flourishment of your lawns naturally occurring beneficial microorganisms. As the biological life in your soil improves over time then the thatch layer starts breaking down faster than it would otherwise.
There are a number of companies that make thatch removal products that can be applied to the lawn. Many of them contain similar mixtures of ingredients with some deviation however most of them are based on a combination of humic acids and molasses.
You can see this post on the site for a comparison of the most common liquid thatch removers for sale today.
In my lawn I use liquid thatch removal products regularly and when cores are pulled you can clearly see that lower layers of thatch are slowly transforming into soil now compared to when they were stagnant in the lawn previously.
This is a slow process though and the best way to speed it up is to introduce air and oxygen flow into the thatch layer. The electric dethatchers discussed about can help with this as can the deeper cutting verticutters and scarifiers that you typically hire out to local service providers but the best way of getting the job done is to core aerate your lawn twice a year before your lawns typical growing season.
Cold season lawns are best aerated at the beginning of Spring and the end of summer while warm season lawns are best aerated at the end of Spring and the beginning part of summer.
How Core Aeration Can Be Used To Remove Thatch From A Lawn
Mechanical core aerators typically pull ¾” wide plugs out of the ground that are between 3-6 inches in depth. Most quality core aerators have tines that can be swapped out for your desired result but the takeaway here is that cores pulled will extend through the entirety of even the worst thatch layers and into the underlying soil.
This is beneficial because it introduces the most air and moisture into and below the thatch layer creating the aerobic environment necessary to decompose thatch efficiently.
Not only do cores help create the perfect environment for decomposition of thatch but they also physically remove a portion of the thatch without ripping up all the grass and root systems in the lawn.
A single soil core pulled that is ¾” wide is removing the same surface area of thatch…completely. If you were to pull the recommended 24 cores per square foot then a single core aeration session can remove roughly 7.5% of all thatch from your lawn in a single day!
In my lawn I core aerate twice a year meaning a full 15% of all of my thatched is completely removed from my lawn annually when I core aerate. The cores are then removed from the lawn and I’m able to top-dress the lawn with beneficial stuff like Azomite, biochar, compost, and worm castings. The process of core aeration gives me the opportunity to add quality soil amendments under my soil surface, remove a portion of my thatch and leave my actual turf grass in a healthy state, ready for a thorough root expansion in the zone below the thatch layer.
Which leads me to my next point. All of these techniques can manage and remove thatch from a lawn but when they are all done together they work much faster and more efficiently. It’s the prime example of 1+1=3.
Do Multiple Thatch Removal Techniques Simultaneously For Maximum Benefit
If you core aerate and top-dress just before you run a scarifier or electric dethatcher over the lawn in the same season that you begin a regimented liquid thatch program you can quickly take a bad thatch problem in the lawn and improve it much faster than anyone else only taking one of the steps.
If you are looking to remove thatch in your lawn and you are serious about it then I suggest you take a look at any of the following pages on this site where I compare your best options (and the value options) in each product category.
I have fully reviewed the best and most commonly purchased electric dethatchers on the market here. I own a few of them myself and I know that each of them have their own pros and cons.
You can also see this post for my comparison of the best liquid dethatch products (and cheapest) on the market today.
As for thatch rakes they are all very similar. I’d recommend you just go to your local home and garden store and buy whatever they have on the shelf. I use the Ames rake and made a full video about it here but in all honesty I’m sure most of them are similar enough that it doesn’t make a difference which one you buy.
For electric scarifiers and dethatchers I like the Billy Goat CR550HC because it is somewhat affordable compared to others (still very expensive though) and has one of the deepest cutting depths of them all at a full ¾”.
These big machines are only for people with lots of disposable income though…for the rest of us whatever gas-powered dethatcher your local tool rental company has to offer will probably be just fine and will probably offer more power and a greater cutting depth than any of the low cost electric options on the market.
Good luck with this project! It’s will be a lot of hard work and no matter how you look at it will be time consuming…but it will be well worth the effort for a variety of measurable reasons. Her are a few articles that should help you understand thatch even better: