What is a Scarifier, And How Does It Help Your Lawn?

There are many ways we can care for our lawns to give them the greatest chance to survive hot summers and harsh winters. Scarifying is one of the more extreme methods to really get rid of any unwanted build-up clumped around vulnerable grass blades and roots. Somewhere between dethatching and tilling, scarifying is a suitable process that needs to be implemented carefully and correctly.

Key Points:

  • Scarifying is a process of digging into a lawn that removes unwanted debris and grass clippings.
  • Preparing the lawn for scarifying includes killing moss/fungus, evening out surfaces, waiting for dry ground, and mowing grass low.
  • During and after using a scarifier, removing thatch frequently and applying slow-release fertilizer helps restore a healthy-looking lawn.

If normal dethatching methods and aeration techniques are not cutting it, you may need even more powerful cutting tools like a scarifier. Read on to learn about these high-speed steel tools and the aggressive process of scarifying your lawn for improved turf health. 

What Is Scarifying?

Scarifying is a process of digging into a lawn that removes yard debris and grass clippings that have accumulated on and underneath the soil. Similar to a milling machine, sharp blades cut into the ground and shred entirely anything in their path. This is essential in neglected lawns that need more than routine lawn care or to deal with really stubborn thatch.

A properly scarified lawn is the perfect base for new turf to be laid down and can help prevent prevalent weeds from establishing early. 

How to Help Your Lawn with a Scarifier?

Sun Joe AJ805E 15-Inch 13-Amp Electric Dethatcher and Scarifier w/Removeable 13.2-Gal Collection Bag, 5-Position Height Adjustment, Airboost Technology Increases Lawn Health, Green

A scarifier can prevent a lawn from suffocating under a thick layer of thatch and provide much-needed aeration after a long hot summer. When compaction and thatch have reached the point that your turf is starting to suffer, you will want to scarify your lawn. To help prepare your lawn for this process, there are a few things you can do. 

Kill Moss or Fungus

Invasive species in our lawns that spread with airborne spores should be killed with the proper product before using a scarifier. Often lawns with thatch buildup also have fungal problems and so treating the lawn with a fungicide prior to using these high-powered devices with steel blades could spread spores throughout the entire yard. 

Level Uneven Surfaces

Using a surface planer or a lawn roller in the early spring will make your scarifying in the fall much easier. If the lawn is uneven, then there is a chance the lawn scarifier’s rotating cylinder won’t penetrate the soil deep enough for aeration and dethatching. Evening out the entire lawn will ensure robust growth after lawn maintenance. 

Wait Until the Moisture Level is Low

It is best to dethatch your lawn when the ground is not too wet. Soggy thatch is heavy, and you and the machine will have to work much harder. Pushing a manual machine over a spongy lawn can be exhausting, and lawn debris is harder to disengage from plant roots when they are wet. 

Mow Grass Low

Before running a scarifier or lawn dethatcher, make sure to mow the grass to the lowest setting that still protects your healthy lawn. Do not scalp the turf, or your clean and well-maintained lawn may die and need to be entirely replanted. Mow low but allow 2 to 3 inches or more if dealing with a fescue grass lawn. 

Go Slow and Steady

Rushing the machine will result in lackadaisical results, and some organic matter will be left behind to continue suffocating grass roots. Lawn scarifying should be thought of as a mild form of tilling, and any cutting lawn with blades should be done slowly to avoid hitting concrete joints or tree roots. 

Dump or Rake Up Thatch

As the thatch builds up on top of the soil or in collection bags, make sure to remove it frequently. Letting bags get too full affects the scarifier’s ability to keep working, and piles on the grass should be removed before they harm the grass blades. 

Apply a Slow Release Fertilizer

Once you have sacrificed, give your lawn the best chance of bounding back in the spring with a slow-release fertilizer high in nitrogen. Depending on your climate and the time of the year you dethatch your lawn, you may or may not need to run the lawn mower once or twice more before winter dormancy sets in. Mow high to allow for fast growth of the roots of lawn grass. 

What Time of Year is Best to Scarify? 

Scarifying your lawn in the late summer or early fall is best due to a number of factors. In the fall, you can remove the entire thatch pile that has been building up all year. While some lawns might need a dethatching in the spring if winter has active turf growth, most lawns, regardless of grass type it climate, will benefit from a once-a-year maximum scarifying.

Based on the level of thatch by fall, you may choose to skip thatch removal with a scarifier and opt to get rid of thatch in spring. When there is heavy thatch, you may need the more invasive thatch removal procedure of scarifying to prevent dangerous thatch accumulation.

Scarifier vs Dethatcher

Rock&Rocker 15 INCH 13Amp Electric Dethatcher Scarifier, 2-in-1 Dethatcher Aerator, 5 Working Depth, 45L Thatch Bag, Tool-Free & Foldable Handle, Easy Storage, 3 Rod Handle Height, for Lawn Health

Both a lawn scarifier and a dethatcher are useful tools that can help you promote fresh lawn growth. The degree to which the lawn is restored and how long it takes for your turf to bounce back depends on which method you use.

Dethatching can be a regular lawn maintenance technique, whereas scarifying is much more drastic and only used before a complete lawn restoration project. Most of the time, you will not need to do both, as the results would likely lead to a dead lawn that needs to be re-sodded or re-sown.

Removes Whats Beneath ThatchX 
Aerates the LawnXX
Removes ThatchXX
Frees Roots from EntanglementX 
Slow Grass RecoveryX 
Rapid Grass Recovery X

Is Scarifying My Lawn Necessary?

It is hard to know if scarifying is necessary for every yard specifically, but in general, there are signs that scarifying may be the best solution for severe thatch. A thatch barrier prevents water and nutrients, as well as oxygen, from reaching the roots of plants where they can be utilized.

Grass will suffocate under these symptoms of thatch, and in order to prevent this, drastic actions like scarifying may be needed for your lawn. 

If a dethatching rake or power rake has not restored the health of your turf, you may want to consider scarifying. Several layers of thatch below ground level can pose a problem, and only the shape blades of a scarifier can shred and lift those out without obliterating the grasses roots.

You may also need to scarify your lawn if you want to avoid aerating separately from running a dethatcher, as a scarifier will complete both of these tasks in one pass. While a tedious and tiring process, scarifying might just be what your lawn needs to get rid of aggressive thatch buildup.