Scarifying your lawn

Scarifying helps rejuvenate thick, spongy lawns by removing thatch and excess root build-up. Learn when and how to scarify your lawn in South Australia for lush, green results.

Summary

If your lawn feels thick, spongy, or discolours every time you mow it, it’s probably time to scarify. Scarifying removes the build-up of thatch and dense root matter that prevents air, water, and nutrients from reaching the soil. The result is a healthier, tighter, greener lawn. In South Australia, scarifying is suitable only for Couch and Kikuyu lawns and is best done from October through February. This guide explains how to do it step-by-step, what to expect during recovery, and what to do if you have Buffalo instead.

What Is Thatch and Why Does It Matter?

Over time, warm-season grasses like Couch and Kikuyu tend to develop a thick, spongy layer of thatch — a straw-coloured mat made up of dead roots, stolons, and stems that sit between the soil and the leaf blades.

When thatch builds up too much, it acts like a barrier. Air, water, and nutrients can’t reach the root zone effectively, and your lawn starts to suffer. You’ll notice:

• The mower scalping and exposing brown patches after mowing
• A springy, uneven feel underfoot
• Slower growth and poor colour, even after fertilising

In severe cases, the roots begin to grow into the thatch layer rather than the soil, leaving your lawn vulnerable to heat stress, pests, and drought.

When it comes to thatch, the interesting thing about couch and kikuyu varieties is that the blades of the lawn only ever occupy the top 10-20mm of the lawn. When a lawn gets spongy, it's the thatch layer getting longer, not the blades. For example, a 100 mm-tall lawn might have 80 mm of thatch and only 20 mm of green blades - as seen in the thatch diagram in this blog.

When this happens, the first thing you remove is the blades, exposing the brown underlayer. The natural reaction is to mow higher — but that only makes the thatch longer! The right fix is to remove it entirely and maintain a lower, more frequent mowing schedule.

When and Why to Scarify

Scarifying is best done when your lawn is actively growing and can recover quickly — typically from October through February in South Australia. Attempting it in cooler months can cause lasting damage, as the grass won’t regenerate before winter. 

Scarifying:

• Removes compacted thatch and old root matter
• Improves air and water flow to the soil
• Encourages new stolon and rhizome growth
• Restores colour and density

For most lawns, every two years is enough. However, high-traffic areas or heavily fertilised lawns may need it annually.

How to Scarify Your Lawn (Step-by-Step)

Step 1: Mow Low and Remove the Thatch

Begin by mowing your lawn down to the soil surface using your regular mower. Gradually lower the blades until you can just see soil across most of the lawn. Don’t worry — Couch and Kikuyu can handle aggressive mowing.

Be prepared: you’ll remove a surprising amount of material. It’s worth planning disposal ahead of time, as you may fill several green bins - even a trailer full!  After mowing, your lawn will look brown and bare — that’s completely normal. Within days, you’ll see fresh green shoots emerging.

Tip: If you only have a light thatch layer, this “scalping” mow alone may be enough to rejuvenate your lawn.

Step 2: Scarify the Root Zone

For heavier thatch or compacted lawns, hire a scarifying machine (vertimower). These machines use vertical blades to cut through the soil surface and lift out dense organic matter that mowers can’t reach.

Run the machine in two directions (north–south and east–west) for best results. This opens the root zone and allows oxygen, water, and nutrients to reach the lower layers of the soil, stimulating new growth from below.

After scarifying, rake up all debris and remove it from the lawn — this ensures no dead material is left to recompact.

Safety note: Always wear eye and ear protection when operating machinery, and avoid scarifying during extreme heat.

Step 3: Apply a Wetting Agent and Fertiliser

Once the lawn is clean and open, it’s time to feed and hydrate it.

1. Apply a liquid wetting agent to ensure even water penetration and help the soil re-wet evenly after compaction.

2. Follow up with a complete fertiliser, such as Paul Munns Greenkeeper, which provides balanced nutrients for rapid regrowth and vibrant colour.

Water thoroughly afterwards, keeping the soil moist for the next few weeks to encourage recovery.

What to Expect After Scarifying

Immediately after scarifying, your lawn will look like it’s been through a disaster — brown, flat, and patchy. Don’t panic! Within 4–6 weeks, your lawn will return thicker and greener than ever.

During this time:

• Water regularly (daily for the first week (if it doesn't rain, then taper off)
• Avoid mowing for at least 2 weeks
• Keep foot traffic to a minimum until new shoots establish

Growth rates depend on temperature — a mild spring may delay recovery slightly, but once warm weather arrives, Couch and Kikuyu respond vigorously.

Pro tip: Combine scarifying with coring every second cycle to improve drainage and soil aeration even further.

What If You Have Buffalo?

Buffalo lawns (like Sir Walter or Kings Pride) are different. They have no underground runners (rhizomes) and grow primarily from above-ground stolons. This means that you can't scarify a buffalo lawn under any circumstances.  If your buffalo lawn gets thatchy, you can reduce the thatch height in the following way:  

1. Lower your mower one notch below your normal height.
2. Leave some green leaf behind — don’t remove all colour.
3. Wait 3-4 weeks for recovery before repeating.
4. Continue gradually until the thatch is thinned out. 

This gentler process may take several months, but it’s much safer for Buffalo. Always keep the mowing height above 40 mm, and only attempt this between October and March.

Maintenance Tips to Prevent Future Thatch

• Mow frequently, not high. Shorter intervals mean you’re removing less each time, reducing stress and thatch accumulation.
• Avoid over-fertilising. Too much nitrogen produces lush, spongy growth that contributes to thatch build-up.
• Use a soil wetting agent every 2–3 months during the growing season to improve water movement.

Need Help?

If you’d like advice or professional assistance with scarifying your lawn, call Paul Munns Instant Lawn on (08) 8298 0555 or email info@paulmunnsinstantlawn.com.au.
Our team can assess your lawn type, condition, and season to recommend the right approach.

Frequently Asked Questions

Q: How often should I scarify my lawn?
A: Every two years is ideal for most Couch and Kikuyu lawns, but if your lawn becomes thick and spongy sooner, it may need it annually.

Q: Can I scarify in winter?
A: No. The grass is dormant during winter, so recovery is too slow. Only scarify when your lawn is actively growing — between October and February.

Q: What’s the difference between scarifying and dethatching?
A: Dethatching removes the surface thatch layer. Scarifying goes deeper, thinning out the root zone and removing dense organic matter.

Q: How do I know if my lawn needs scarifying?
A: If your mower scalps the grass even at higher settings, or your lawn feels spongy and loses colour easily, it’s time to scarify.

Q: Will scarifying damage my lawn?
A: It may look rough immediately after, but with proper aftercare, your lawn will recover thicker and greener than before.