- What Does a Lawn Scarifier Do?
- Is a Lawn Scarifier the Same as a Dethatcher?
- Lawn Scarifier vs Aerator
- How Much Do Lawn Scarifiers Cost
If you own property, I’m willing to bet you own some type of lawn mower. You might also own basic tools like a weed whacker or leaf blower. But these items are just the tip of the iceberg when it comes to the different types of lawn equipment on the market.
One tool you may not be familiar with is a lawn scarifier. While you won’t find this piece of equipment in the average person’s garden shed, it’s a handy tool that makes removing thatch and other debris a piece of cake.
In this article, I’ll tell you all about lawn scarifiers and why (or why not) it’s worth investing in one. I’ll also offer some expert tips for getting the best results from your lawn scarifier each time you use it.
What Is A Lawn Scarifier?
A lawn scarifier is a type of lawn equipment that features a metal cylinder — similar to a rotary mower — fitted with several blades or teeth. As the cylinder rotates, these blades slice into the soil and pull thatch and other debris.
At first glance, a residential lawn scarifier may resemble a regular walk-behind mower. Both electric- and gas-powered models are available. I find that manual push-operated models also tend to be very popular among regular homeowners.
Many lawn scarifiers have adjustable blades. This feature allows you to customize the depth at which the blades slice into the soil and remove debris.
Some scarifiers also come with built-in collection systems. These models deposit lifted thatch and debris into a bag or bin for easy removal. Lawn scarifiers that do not have a collection compartment deposit loose debris back onto the lawn’s surface to be raked up later. You can find a large selection of Lawn Scarifiers at stores such as Amazon.com or Home Depot.
What Does a Lawn Scarifier Do?
The primary purpose of a lawn scarifier is to remove all thatch as well as any other debris in the top layer of soil. When used correctly, a scarifier can improve lawn health by increasing its access to things like light, water, and oxygen.
Because lawn scarifiers cut into the soil with blades, they also offer some of the same benefits as an aerator. If your lawn is otherwise healthy (i.e., not compacted), additional aeration may not be necessary after scarification.
Additional benefits of using a lawn scarifier may include weed control and a thicker lawn over time. In my experience, scarification is most effective against weeds that spread via rhizomes and stolons. Your lawn may grow thicker after using a scarifier due to the removal of dead roots and grass blades.
A lawn scarifier is an excellent investment if your lawn also struggles with moss growth. This tool is very effective at pulling up moss without causing excessive damage to the surrounding turf grass.
Technically speaking, you can achieve similar results using a metal rake. But a lawn scarifier makes it easier to dethatch large areas and can penetrate much deeper into the soil than is generally possible by hand.
Despite all of these benefits, it’s important to keep in mind that scarification is inherently damaging to turf grass. Your lawn may appear less healthy immediately after the use of a scarifier. Also, lawn scarifiers should never be used on grass that is stressed, dormant, or not yet established.
Is a Lawn Scarifier the Same as a Dethatcher?
Put simply, a lawn scarifier is a more intense version of a traditional dethatcher. Both machines perform the same job but to varying degrees.
Unlike scarifiers, dethatchers typically remove just part of the thatch layer. This improves lawn health without causing undue stress and damage to the root system. Many grass species actually respond better to the use of a dethatcher due to this lower intensity.
Routine dethatching is ideal for the control of thatch buildup in most turf species. Using a dethatcher instead of a scarifier maintains a thin layer of plant debris that actually protects the soil and surface grassroots.
A dethatcher may be a better long-term investment depending on the type of grass you’re growing and the general state of your lawn as a whole. Personally, I prefer to use a dethatcher for routine maintenance unless the lawn is seeded with fescue grass or is otherwise prone to heavy thatch accumulation.
Lawn Scarifier vs Aerator
Though they may look similar, a lawn scarifier and an aerator have completely different purposes.
While lawn scarifiers remove built-up thatch and debris, aerators pierce the soil to create small holes. These holes allow water, oxygen, and nutrients to better penetrate the soil and reach plant roots. Holes created by aeration may also create a better environment for beneficial soil-borne microbes to thrive.
Aeration is used to improve soil quality and compaction, and its benefits sometimes overlap with dethatching and scarification. According to the University of Minnesota, routine aeration reduces the rate of thatch buildup. However, a well-rounded lawn care routine may still require both pieces of equipment for the best results. You can pick up this heavy-duty lawn aerator from Ace Hardware here.
How Much Do Lawn Scarifiers Cost
While a scarifier is a more specialized piece of equipment than a lawn mower, residential models are surprisingly affordable. There are many basic, walk-behind machines available for $200 or less.
You may be able to purchase a scarification attachment for your existing lawn mower as well. These attachments are typically made for riding lawnmowers and retail for a similar price as standalone options.
If you’re interested in one-time lawn scarification to address an extremely built-up layer of thatch and debris, rental may be a better option. I recommend reaching out to local lawn equipment rental companies to inquire about availability. Or you can hire a landscaping professional to perform scarification for a premium cost.
When To Scarify Your Lawn
I recommend lawn scarification once per year except in cases of extreme debris and thatch buildup. Using a lawn scarifier any more frequently than this is likely to cause damage to the grass. Personally, I prefer to use a dethatcher for annual thatch removal to prevent excess root damage.
Do not use a lawn scarifier on turf grass that is less than a year old. This includes lawns that have been overseeded within the past year. Young grassroots are not established enough to hold up to scarification and may be slow (or fail) to recover.
The best time of year to scarify your lawn is when the grass is at its peak growth. For most grass varieties, this will be in the late spring, early summer, or fall.
Regardless of grass type, scarifying too early or late in the year will leave grass vulnerable to seasonable damage. If you use a lawn scarifier too early in the spring, the grass will not have time to recover from the stress before the summer heat. The same is true of scarifying too close to the onset of winter.
For spring scarification, mid or late April is ideal. However, you should not use a lawn scarifier on damp turf. If the spring has been particularly wet, wait to scarify until the ground dries up.
In the fall, I don’t recommend using a lawn scarifier any later than September or October. You should err on the side of caution and scarify earlier in the year if your area is prone to an early frost.
Prepare Your Lawn Before Using A Lawn Scarifier
To get the best results from a lawn scarifier, you first need to prepare the grass.
I highly recommend mowing the grass prior to scarification and removing any loose debris from the soil’s surface. I also suggest treating weeds and moss before using a lawn scarifier.
After scarifying your lawn is a great time to apply soil amendments and grass seed. Take full advantage of this when scheduling the rest of your lawn maintenance for the year.
Apply a Herbicide Treatment To Clear Weeds and Moss
Although lawn scarification can help control things like weeds and moss, it’s best to treat the area with chemical herbicides prior to using a scarifier.
I recommend applying a selective herbicide to your lawn at least 3 weeks before you plan to scarify. Make sure your chosen formula is designed to target the weed species in your lawn and is safe to use on your particular grass type. By applying a weed killer before scarification, the scarifier will have a chance to remove any leftover dead plant matter from the soil.
Treating moss is especially important if you intend to scarify your lawn. Operating a lawn scarifier over living moss can help to remove it. However, it is also likely to release active moss spores into the area.
These spores can then germinate and grow in other parts of your lawn and garden. To prevent this, apply a dedicated moss killer about 1 week before scarification.
Mow Your Lawn Short
Short turf offers easier access to the thatch layer and topsoil. Mowing the grass short prior to scarification will make the entire process much more effective.
In my experience, the general advice is to mow the grass down to about 1 inch prior to lawn scarification. The ideal height for your grass may vary depending on its exact type.
With that said, you should not cut your lawn to this height in a single mowing session. Removing more than one-third of your lawn’s height at a time will cause extreme stress. Instead, I recommend gradually lowering your mower blades over several sessions. This may take a couple of weeks, so be sure to plan accordingly.
It’s also a good idea to collect any grass clippings using a bag attachment.
Clear Debris, Clippings, or Dead Organic Material
The last step before lawn scarification is to clear away any obvious debris. Start by cleaning up things like fallen branches and leaves using a rake or leaf blower.
I like to use a metal rake to pull up any loose thatch, moss, or weeds. While this may seem redundant, it will make your lawn scarifier more efficient overall. Removing material that can be easily lifted by hand will allow your scarifier’s blades to slice deeper into the soil.
Scarify Your Lawn
Start working in one direction with the scarifier blades at a relatively high setting. After treating the entire lawn, switch directions so you’re working at a right angle to your original pass. Lower the blades slightly to lift even more thatch and debris from deeper into the soil.
In many cases, two passes will suffice. If a thick layer of thatch still remains, you can continue treating the lawn. I don’t recommend doing more than four passes at a time. Keep alternating directions and lowering the blades with each pass.
Finish With Rich Topsoil Dressing
I highly recommend following up on lawn scarification by applying a thin layer of organic material or rich topsoil to the area. This simple step can improve overall soil quality by boosting drainage, nutrient content, and the presence of beneficial microbes.
Topdressing your lawn is especially effective against soil compaction (though I still recommend treating the ground with a core aerator for optimal results).
Overseed If Required
If your lawn was thin or patchy prior to scarification, this is a great time to overseed to fill in those spots. Overseeding simply means sowing new grass seed over an existing lawn.
You can use overseeding to repair sections of lawn damaged by heavy foot traffic, dog urine, or general wear and tear. It’s even possible to overseed using a different grass type than what is already growing on your lawn. Doing this is a wonderful way to address weak spots in your existing lawn — e.g., shade tolerance, drought tolerance, or growth rate.