Dethatching Lawn Mower Blades Explained | Do They Work?

Are you considering buying dethatching blades for your lawn mower?

In this guide, we’ve explained what dethatching lawn mower blades are, and if they really work.

Let’s get started.

What are dethatching lawn mower blades?

Arnold dethatching lawn mower blade.
A dethatching blade for your lawn mower is a special type of blade that is designed specifically to help with scarifying your lawn.

There are two different types of dethatching blades:

  1. Those with a wire tine on each end of the blade (these are the most common and most effective type).
  2. Those with a nylon line included. These are less effective and are best avoided, as they can damage your lawn. While a metal tine will collect the top layer of thatch quite nicely, nylon will destroy everything in comes into contact with.

How do dethatching blades work?

As your dethatching blades spin, they cut the grass, just like regular mower blades, using the cutting edge of the blade.

However, at the same time, they also dig into the thatch on your lawn, digging it out, and ultimately sending it into your mower’s grass box.

Essentially, the metal spring at the end of the blade does the hard work of removing thatch. It trails slightly behind the blade, cutting up the thatch, and ripping it out of your lawn.

At this point, the thatch is sucked into your mower’s grass box. It’s important to avoid having your lawn mower on a mulching setting when using a dethatching blade.

Do dethatching lawn mower blades work in practice?

Thatch cleared from a lawn.

Dethatching mower blades do work, however they are not as effective as using a lawn rake or a proper lawn scarification machine (also known as a power rake).

Using dethatching blades, you will be able to remove some of the top layer of thatch, provided your lawn mower is powerful enough. This will increase the amount of sunlight that reaches your lawn’s root system, and also improve airflow, which can improve the health of your lawn.

However, you won’t be able to completely dethatch your lawn with this type of mower attachment, especially if you have a deep layer of thatch.

Also, dethatching blades are not a good choice if you have a large garden. They’re best used on small lawns, since they’re not a very efficient way to dethatch a lawn.

Advantages of dethatching mower blades

Despite what we mentioned above, there are still a number of benefits to using a dethatching blade on your lawn mower to dethatch your grass.

  • They’re very cheap when compared to the other methods available to dethatch your lawn.
  • They’re simple to install and use.
  • They allow you to dethatch and clear moss from a small lawn quite quickly.
  • You don’t have to clean up much once you finish dethatching your lawn, especially if you have a good quality mower that successfully sends your grass clippings and thatch into its grass box.

Disadvantages of dethatching mower blades

Arnold dethatching lawn mower blade.

There are also a number of disadvantages of using a dethatching mower blade.

  • You will need a powerful lawn mower, ideally a large, petrol rotary lawn mower. This is because the metal claws on the end of a dethatching blade need a lot of force to cut up and pull out your thatch. If you don’t have enough power, you risk burning out the motor of your lawn mower.
  • You can’t use dethatching blades when the grass is too long, or too damp. This will also increase the risk of damaging your lawn mower when mowing. The thatch can’t be more than an inch thick, otherwise the dethatching blade will be ineffective.
  • It might be hard to find a dethatching blade that works with your specific lawn mower. Since mower blades are not universal, you’ll need to find a dethatching blade with the right blade length and bolt size.

Alternatives to dethatching blades

Rather than removing thatch using a dethatcher blade attachment, you can also use one of these alternative solutions.

1. Scarifiers

Effect of scarifying on the look of a lawn.

Lawn scarifiers look a lot like lawn mowers, except they have metal blades that make shallow incisions into your grass, helping to remove thatch. These machines may be electric or petrol-powered.

The main advantage of using a scarifier is its efficiency. You’ll be able to scarify a lawn very quickly, even if you have a significant thatch problem.

Also, scarifiers help to cut the stolons of your grass, encouraging stronger grass growth. A dethatching blade cannot do this, as it does not cut deep enough into the ground.

If you need to dethatch your lawn properly, a scarifier is the way to go. You can also rent these machines, especially the industrial petrol-powered ones, which is a good idea if you only need to use a dethatcher once a year or so.

2. Lawn rakers

Darlac lawn scarifier.
If you’re looking for a more simple solution, that’s a bit more effective than using a dethatching blade when mowing, you can also consider a lawn raker.

These bits of kit are typically designed as a metal bar, with steel blades coming off it, attached to two wheels at each end. The metal bar also has a handle, for you to push.

As you push the raker along the grass, the blades cut into your thatch, and pull it up. You can also adjust the depth of the blades, depending on how deep you want to scarify your grass.

Most lawn rakers do not have their own power – you have to push them. As a result, they don’t cost much, but can be a little inefficient if you’re looking to dethatch a large lawn.

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