It's time to core your lawn

Learn why lawn coring (aeration) is essential for Kikuyu, Couch & Buffalo lawns in spring. Improve soil health, drainage & resilience with annual coring.

Summary: 

As soil temperatures begin to rise in late winter and early spring, warm-season lawns like Kikuyu, Couch, and Buffalo start to wake from dormancy. This transition period is the perfect time to give your lawn a boost with coring (aeration). Coring improves oxygen levels, reduces compaction, increases water penetration, and enhances root growth, setting your lawn up for a stronger, greener summer. Whether you do it yourself with a hired machine or hand tool, or hire a contractor, coring is one of the best preventative maintenance practices for long-term lawn health.

What Is Lawn Coring (Aeration)?

Lawn coring, also known as lawn aeration, is a process where thousands of small plugs of soil are physically removed from your lawn. Each plug is generally:

• 20mm wide
• 100mm deep
• Spaced around 150mm apart

The result is a lawn surface full of evenly spaced holes. While it might look unusual at first, these holes are the key to improving your soil’s ability to breathe, drain, and feed your grass. The plugs (or cores) are usually left on top of the lawn initially and then collected and disposed of, as leaving them to break down can contribute to further thatch build-up.

Why Lawn Coring Matters

1. Increases Soil Oxygen

Grass roots need oxygen just as much as they need water and nutrients. Over time, soil naturally becomes compacted, especially in high-traffic areas such as backyards, sports fields, and nature strips. Compaction squeezes out the air pockets in the soil. Coring reintroduces air, giving roots the oxygen they need to grow vigorously.

2. Reduces Thatch Build-Up

Thatch is a spongy layer of dead roots, stems, and organic matter that sits between the green grass and the soil. Too much thatch blocks water and nutrients from penetrating into the root zone. Coring physically removes some of this thatch, creating a healthier balance and preventing disease.

3. Improves Water & Nutrient Movement

Healthy lawns rely on water and fertiliser moving into the soil profile—not sitting on top. Coring creates deep channels that allow water, fertiliser, and soil conditioners to move freely, ensuring your lawn’s root system has access to everything it needs.

4. Relieves Soil Compaction

Compaction is one of the most common causes of poor-performing lawns. It restricts root growth, prevents water infiltration, and creates shallow, weak root systems. Coring breaks through this compaction, opening up space for roots to expand deeper and stronger.

5. Enhances Drought Resistance

A lawn with deep roots is more resilient to heat and drought. By encouraging downward growth, coring makes lawns less reliant on frequent watering and more capable of withstanding Australia’s hot summers.

When Is the Best Time to Core a Lawn?

You can core your lawn at any time of year, but timing is everything for the best results:

• Late Winter :
  Early Spring (August & September):
  This is the ideal time in South Australia and similar climates. Winter rains keep the soil soft, making it easier to achieve deep cores. Meanwhile, rising daytime temperatures signal your lawn is about to grow strongly, helping it recover quickly from the process.

• During Active Growth Periods:
  Never core a dormant lawn. Always choose a time when your grass is actively growing so it can heal quickly and take advantage of the improved soil conditions.

• Avoid Peak Summer Heat:
  Coring in the middle of a heatwave can place stress on your lawn. If you miss the early spring window, aim for mid-to-late autumn instead.

How to Core a Lawn: DIY vs Contractor

DIY with a Machine

• Most hire shops stock motorised coring machines. They are suitable for medium to large home lawns and are easy to use, though they can be heavy and physically demanding.

DIY with a Hand Corer

• These are best for small lawns or spot treatments. Tools like The Multi Corer (Australian-made, with interchangeable tines) are designed to last a lifetime. The Multi Corer offers flexibility to switch between solid tines (to punch holes) and hollow tines (to remove plugs).

Hire a Contractor

• Professionals use heavy-duty equipment with deeper penetration. This is the best option for compacted soils or very large lawns and will save you the effort while delivering superior results.

What To Do After Coring

The real magic happens in the weeks following coring. Here’s how to make the most of it:

1. Fertilise: Apply a slow-release fertiliser such as Paul Munns Greenkeeper straight after coring. Nutrients will move deeper into the soil profile, right where the roots can absorb them.
2. Water Thoroughly: Give your lawn a deep soak to encourage roots to follow the moisture downwards.
3. Top-Dress: It's a good idea to lightly topdress after coring to fill the core holes in. This ensures the core holes remain open and creates channels for water to penetrate through the summer months. 

How Often Should You Core?

• As Preventive Maintenance:  Once a year is ideal for most home lawns.
• For Problem Lawns: Twice a year may be beneficial if you have clay soils, heavy compaction, or drainage problems.
• Sports & High-Traffic Lawns: These may require more frequent coring to stay healthy.

Final Word

Lawn coring is one of the most beneficial yet under-used practices in lawn care. By oxygenating the soil, reducing compaction, and improving water and nutrient flow, it creates the perfect conditions for a healthier, stronger lawn. Done annually, it can drastically reduce your watering and fertilising needs while making your lawn more drought-tolerant and resilient through summer.

Whether you DIY with a machine, invest in a hand tool, or hire a contractor, coring is an investment in long-term lawn health. Combine it with best-practice mowing, fertilising, and watering, and your lawn will reward you with lush green growth year after year.

Frequently Asked Questions About Lawn Coring

Q: Will coring damage my lawn?
No. While it may look rough initially, lawns recover quickly—usually within 2–4 weeks during active growth.

Q: Can I mow straight after coring?
Yes, but you may want to wait a few days to allow the holes to settle.

Q: Should I leave the cores on top?
It’s better to rake them up. Leaving them can lead to uneven breakdown and add more thatch.

Q: What’s the difference between hollow and solid tines?

• Hollow tines remove plugs of soil, best for reducing compaction and thatch.

• Solid tines simply punch holes, useful for light aeration.

Q: Is coring the same as spiking?
No. Spiking involves pushing solid tines into the soil without removing plugs. While it improves surface drainage temporarily, it can actually make compaction worse over time. Coring is far more effective.