Scarifier next to wheelbarrow full of thatch

How to Scarify a Lawn

Discover everything you need to know about lawn scarification in our comprehensive guide. From the reasons why to the step-by-step process, we've got you covered.

What is scarification?

Scarification is the removal of thatch, a layer of plant material that accumulates on the soil surface. Thatch consists of dead and living vegetation and should be removed to maintain a healthy lawn.

Why should I scarify my lawn?

A small amount of thatch is beneficial for the lawn.

It helps to retain moisture that would otherwise be lost through evaporation and safeguards the crown of the grass against potential damage from excessive direct sunlight.

However, if not properly managed over time, the accumulated thatch can have a negative impact on your lawn. Once it builds up, the thatch can restrict the flow of air, water, and nutrients to the soil, inhibiting grass growth and increasing the risk of lawn diseases. Therefore, it is recommended to scarify your lawn at least once a year. This practice prevents excessive thatch buildup and its detrimental effects.

When is the best time to scarify?

Mid-spring or early autumn are considered the optimal times to scarify.

Scarification is a tough process for your lawn. Therefore, ideal environmental conditions such as warm weather and plenty of rainfall will encourage new strong growth, speeding up the recovery. Avoid heavy scarification during the hot summer months or when the lawn is dormant throughout the winter.

Guide - How to scarify a lawn.

Things You'll Need
  • Lawn mower
  • Powered or manual scarifier
  • Wheelbarrow
  • Rake

Scarifying your lawn doesn't involve too many steps. However, it's labour-intensive, even more so when using a manual scarifier.

The ground should be dry, as scarifying when wet can damage your lawn. However, avoid scarifying in prolonged heat waves or drought conditions, such as mid-summer, when the lawn is already under stress.

Step 1 - Mow the Lawn
lawn mower and scarifier on a lawn.

To effectively scarify your lawn, it is important to first mow your lawn short. The grass should be around 2-4 cm tall. Using the second lowest setting on most standard rotary mowers should suffice. However, if the grass has grown excessively long, it's better to start with a higher setting and then gradually lower it the following week.

Cutting more than one-third of the grass blade's total height in a single mow can stress the plants, especially when combined with scarification.

Remember to collect the grass clippings as you mow to keep the area clean and tidy.

Step 2 - Scarify
Powered scarifier

You can scarify your lawn using a manual scarifier (or spring-tine rake) or a powered scarifier. However, it's worth noting that manual lawn scarification is a physically demanding task, particularly for larger areas where powered scarifiers are typically essential.

The depth at which you need to scarify depends on factors such as soil compaction and the level of thatch buildup. A depth of 5mm is usually a good starting point, adjusting as necessary.

Operating a powered scarifier is relatively straightforward. Most are self-propelled, with the only adjustment required being the depth of the blades, done similarly to how you would adjust the height of a lawn mower.

Manual scarifiers will require a bit more effort on your part. You will need to keep control of how deep you penetrate the soil while using a back-and-forth "raking" motion to lift the thatch from the ground. A spring-tine rake can be used in the same fashion and can be effective for smaller areas. However, they will become blocked with thatch more frequently than a purpose-built manual scarifier.

Go over your lawn back and forth lengthwise with the scarifier, overlapping as you change direction. Once you've completed this pass, make a subsequent crosswise run, aiming for a 35-45 degree angle from your previous run.

Step 3 - Clear up
Loose thatch with scarifier

After scarifying your lawn, you'll be left with a significant amount of loose thatch that needs to be cleared. While some scarifiers come with bags to catch the thatch, they tend to fill up quickly and require frequent emptying.

It's a good idea to have a rake and a wheelbarrow at hand when scarifying, as you can rake the thatch into piles and remove it using the wheelbarrow.

Additionally, a leaf blower can be a useful tool to help gather the thatch into piles, making the cleanup process even easier.

Next Steps?

That's everything you need to know on how to scarify your lawn.

As mentioned, scarifying is tough on your lawn and may appear slightly worse for wear once complete, particularly in moss-heavy areas that should now be bare.

The next step after scarification is usually overseeding. This process helps create a thicker, denser lawn while also filling in any bare patches.