Why your lawn keeps dying (it's usually the ground)
New turf, same bare patches by February. Most lawns that keep dying have a soil or drainage problem, not a grass problem. How to tell, and what fixes it.
The assumption we're testing
“I'll just lay new turf over the top.”
The grass is rarely the problem
When a lawn dies, most people blame the grass. So they buy new turf and roll it out over the same ground. It looks great for a few weeks. Then the same patches go yellow in the first hot spell.
That's because the grass was never the problem. Grass needs loose soil to root into, water that drains away, and enough sun. Take away any one of those and even the best turf struggles.
Most gardens that keep dying have a drainage or soil problem, not a plant problem. Sort the ground first and the rest looks after itself.
Hard ground that roots can't get into
Walk on a patch of lawn for years and the soil packs down hard. Builders' trucks and bobcats do the same in a week. Roots can't push into packed soil, so they stay near the top, where it's hot and dry.
On new houses, the lawn often sits on a thin layer of soil over rubble or builders' fill. It looks fine from above. Underneath, there's nothing for the roots to grow into.
Try this. Push a long screwdriver into the lawn after rain. If it stops after a few centimetres, the roots are stopping there too.
Water that sits, or water that runs off
Clay soil holds water for days. Roots sitting in wet soil can't breathe, so they rot. Then the same clay dries out and cracks in summer. A lawn on clay can drown in winter and bake in summer.
Sandy soil has the opposite problem. Water runs straight through it and takes the food with it. The lawn dries out a day after you water it.
Low spots and slopes matter too. Water pools in the dips and runs off the high side. If one patch is always soggy and another always dry, the shape of the ground is part of the problem. Our drainage page covers the wet side of this.
Shade, watering and mowing
No grass grows in deep shade. Under big trees or beside a tall fence, even a shade-tolerant grass thins out. The answer might be a different grass, a trimmed tree, or a garden bed instead of lawn. Our guide to choosing turf for Sydney goes through which grass suits which spot.
A quick sprinkle every night keeps roots shallow. A deep soak once or twice a week sends them down, where the soil stays cool. Mowing too short does damage as well. It leaves the soil bare to the sun and weeds move in.
Fixing it properly
Start with the ground. Find out what the soil is and where the water goes. Break up hard ground or bring in good soil for the roots. Level the base so water runs off, not in. Then pick a grass that suits the sun the spot gets.
That's more work than rolling out new turf. But it's the difference between a lawn that takes and one you pay for twice. If you're not sure what's going on under yours, try our garden check, or see how we handle turf and lawns.
Want it done once, and done right? We check the ground first, then plan the work.