G’day, Nikolai here from The Lawn Firm. If you water your lawn and the water sits on top or runs off, you’re likely dealing with hydrophobic soil. I see this across Canberra every summer, especially on clay-heavy and compacted sites. The good news is that you can fix it with a few clear steps. Here’s my simple guide.

What is hydrophobic soil?

Hydrophobic soil repels water. The water beads on the surface and never reaches the roots. The lawn dries out fast and turns patchy. This is common in Canberra’s hot, dry periods and on lawns with thatch or compaction.

Why it happens in Canberra

Clay soils dry, harden, and resist wetting.
Heat and wind strip surface moisture.
Thatch build-up blocks water from the soil.
Foot traffic compacts the profile and closes pore spaces.

Common signs I look for

Water beads or runs off instead of soaking in.
Dry patches that don’t respond to normal watering.
The soil is powdery on top but hard below.
A screwdriver or garden fork is hard to push in.
The lawn looks dull and patchy a day after watering.

Quick tests you can do today

Cup test: Pour a small cup of water on a dry area. If it beads or runs, you have a problem.
Screwdriver test: Push a screwdriver into the soil. If it stops at a few centimetres, the soil is dry and compacted.
Plug test: Lift a small plug. If the top layer is dry while soil deeper down is dusty or hard, water is not penetrating.

How I fix hydrophobic soil (step-by-step)

Mow and clear the surface
I mow slightly lower and remove debris. This opens the canopy and lets water reach the soil.
Core aerate the lawn
I run a core aerator to open channels through the compacted layer. Aeration helps every other step work better.
Apply a quality wetting agent
I use a lawn wetting agent to break the water resistance and help water move through the profile. I apply it evenly and water it in.
Top dress lightly (optional but helpful)
A 5–8 mm sandy loam helps level minor lows and improves contact. This is a great time to overseed thin patches.
Water smart
I water the first application in well, then switch to deep, less frequent watering. This trains roots to chase moisture down.
Follow up
I repeat wetting agent applications through summer as needed. I add wetting agent granules to stubborn dry patches if required.

Watering plan that works in Canberra

After treatment: One thorough soak to move the product into the soil.
Then: Two deep soaks per week in hot weather (adjust for rain).
Always water early morning. This reduces loss to heat and wind.
Avoid shallow daily sprinkles. That builds weak, shallow roots.

Mistakes I fix all the time

Skipping aeration: Wetting agents work better after aeration.
Dumping too much top dressing: Thick layers smother leaf blades.
Watering at night: This invites disease in warm weather.
Treating once and stopping: Hydrophobic soil can return in heat. Keep up light maintenance.

How to prevent dry patch long term

Seasonal aeration in spring or autumn.
Regular wetting agent in the warm months.
Reduce thatch with periodic dethatching.
Balanced fertilising to build a stronger root system.
Consistent mowing height to shade soil and reduce loss.

DIY or call The Lawn Firm?

You can treat a small area yourself. But if dry patch keeps returning, the soil likely needs a full program. I diagnose the cause, aerate correctly, choose the right wetting agent, and set a watering and fertilising plan that fits Canberra’s climate. That means fast results and less hassle.