How to Scarify Your Lawn

What Is Scarifying?

Scarifying is the process of raking or cutting through the surface of your lawn to remove the layer of dead grass, moss, and organic debris that builds up between the grass blades and the soil. This layer is called thatch.

A thin layer of thatch is normal and even beneficial. But when it builds up beyond about 1cm thick, it starts causing serious problems:

• Blocks water from reaching roots
• Prevents air circulation to the soil
• Stops fertiliser getting where it’s needed
• Creates ideal conditions for moss and disease
• Makes the lawn feel spongy and look dull

Scarifying cuts through this layer and physically removes it, opening up the surface so your lawn can breathe, drink, and feed properly again.

How to Tell If Your Lawn Needs Scarifying

There’s a simple test: push your fingers down into the lawn at soil level. Can you feel a spongy, fibrous layer before you hit actual soil?

If that layer is more than about 1cm thick, your lawn will benefit from scarifying. Other signs to look out for:

• The lawn feels bouncy or spongy underfoot
• Water pools on the surface rather than soaking in
• Moss keeps coming back despite treatment
• The grass looks thin even though it’s growing
• Feed doesn’t seem to make much difference

When to Scarify

Timing is everything with scarifying. Get it right, and your lawn recovers quickly and comes back stronger. Get it wrong, and you could set your lawn back months.

Best time: Early to mid-September. The soil is still warm from summer (which helps grass recover quickly), but cooler air temperatures and increasing rainfall reduce stress on the lawn. There’s still enough growing season left for the grass to recover fully before winter dormancy.

Second choice: Late March to mid-April. Spring scarifying is possible, but not ideal. Spring grass is weaker after winter dormancy and recovers more slowly. Only do a light pass in spring — save the heavy scarification for autumn.

Never scarify:

• During summer heat or drought
• When the lawn is stressed or dormant
• After mid-October (not enough recovery time before winter)
• When soil is frozen or waterlogged

How to Scarify Your Lawn

Step 1: Prepare the Lawn

Mow the lawn shorter than usual — around 2–3cm. This makes the scarifier more effective and reduces the amount of green material you’ll remove.

If you have a moss problem, treat it with a moss killer 2–3 weeks before scarifying. This gives the moss time to die off, making it much easier to remove during scarification.

Step 2: Choose Your Method

Small lawns: A spring-tine rake (also called a scarifying rake) is hard work but effective. The wire tines dig into the thatch layer and rip it out.

Medium to large lawns: Hire an electric or petrol scarifier. These are available from most tool hire shops and make the job dramatically easier. A powered scarifier has rotating blades that slice through the thatch layer and lift it to the surface.

Scarifier settings: Start on a shallow setting and adjust gradually deeper. Going too deep on the first pass can damage the grass crowns and slow recovery significantly.

Step 3: Work Methodically

Work in parallel rows across the lawn, overlapping slightly. Then make a second pass at 90 degrees to the first. This cross-hatching pattern ensures you remove thatch evenly and don’t leave strips of compacted material behind.

Step 4: Collect the Debris

You’ll be amazed — and possibly horrified — by how much material comes out. A typical lawn produces bin bags full of dead grass, moss, and thatch. Rake it all up and compost it or dispose of it.

Step 5: Don’t Panic

Your lawn will look absolutely terrible after scarifying. Thin, patchy, brown, devastated. This is completely normal. You haven’t killed it — you’ve just removed a lot of dead material that was hiding the true state of the grass beneath.

After Scarifying: Recovery

Overseed Immediately

Overseed the whole lawn, paying extra attention to thin areas and bare patches. Use 25–35g per square metre for overseeding. The open soil surface left by scarifying is the perfect seedbed — seed-to-soil contact is excellent, which dramatically improves germination rates.

Feed the Lawn

Apply an autumn feed (if scarifying in autumn) or spring feed (if scarifying in spring). For the best results after overseeding, use a pre-seed feed that’s formulated to support germination and early root development without burning new seedlings.

Keep It Moist

New grass seed needs consistent moisture to germinate. Water lightly every day (or twice daily in warm weather) until the new grass is established — usually 2–3 weeks.

Be Patient

Recovery takes 4–6 weeks. The lawn will look worse before it looks better. By week 2–3, you should see new seedlings emerging. By week 4–6, the lawn should be noticeably thicker and greener than before you started.

Common Scarifying Mistakes

Scarifying at the wrong time. Scarifying in summer heat or late autumn gives the lawn no chance to recover. Stick to early September (best) or late March to mid-April (second choice).

Going too deep. Start on a shallow setting and work deeper gradually. Cutting too deep on the first pass can rip out grass crowns and leave you with bare soil that’s slow to recover.

Not overseeding afterwards. Scarifying opens up the lawn beautifully for new seed. Missing this opportunity means bare patches will fill with weeds instead of grass.

Expecting instant results. Your lawn will look awful for 2–4 weeks. This is normal. The results come later — and they’re worth the wait.

Scarifying a weak lawn. If your lawn is already struggling from drought, disease, or heavy shade, scarifying will make things worse. Get the lawn healthy first, then scarify.

Scarifying vs Raking

Light raking with a spring-tine rake removes surface debris and is fine to do in spring as part of general maintenance. This isn’t the same as scarifying.

Scarifying goes deeper — it physically cuts into the thatch layer and removes it. Raking might tidy the surface, but it won’t solve a thatch problem. If your lawn has a spongy, thick layer of thatch, it needs scarifying, not just raking.

Consider combining scarifying with aeration for the best results. Scarifying removes thatch from the surface; aeration relieves compaction in the soil beneath. Together, they give your lawn the best possible conditions for healthy growth.

Most lawns only need scarifying once a year (in autumn) or even every other year if thatch buildup is minimal. For a complete overview of seasonal tasks, see our lawn care guide.

Frequently Asked Questions

How often should I scarify my lawn?
Most lawns benefit from annual scarifying in autumn. If your lawn doesn’t build up much thatch, every other year may be enough. Check the thatch depth each September and decide based on what you find.

Will scarifying kill my lawn?
No — it just looks that way temporarily. Scarifying removes dead material, not living grass. As long as you scarify at the right time and overseed afterwards, your lawn will come back thicker and healthier.

Can I scarify in spring?
Yes, but autumn is better. Spring grass is weaker and recovers more slowly. If you do scarify in spring, keep it light — a single shallow pass rather than the deep, multi-directional treatment you’d do in autumn.

Should I aerate as well as scarify?
Ideally, yes. Scarifying removes thatch; aerating relieves soil compaction. They complement each other perfectly. Aerate after scarifying for the best results.

How long after scarifying can I use the lawn?
Keep foot traffic to a minimum for 2–3 weeks to give new seed time to germinate and establish. After that, light use is fine — but avoid heavy traffic until the lawn has fully recovered (4–6 weeks).