Lawn problems: how to work out what's wrong with your lawn

A patch of lawn that has browned off, thinned out or stopped growing looks much the same whatever caused it. Grubs, drought stress, a fungal disease, compaction, a shady corner and a dog that always uses the same spot can all produce the same photograph, and the treatment for one of them will do nothing for the rest. So the guides here are organised by what you can actually see and confirm in your own lawn, rather than by the chemistry you would eventually buy.

Problem guides

Each one covers the same ground: how to tell that is what you have, how to confirm it before spending anything, what to apply and at what rate, and when in the Australian season it matters.

  • Lawn grubs and armyworm

    Two different pests get called lawn grubs and they need opposite watering-in steps. Twenty minutes under a wet towel tells you which one you have.

    Signs that point here

    • Turf that feels spongy underfoot and lifts like carpet
    • Runners chewed back to the stolon
    • Patches that brown off suddenly with no change to watering or feeding
    • Birds, wasps or animals digging the same spot over and over

    Read the lawn grubs and armyworm guide

  • Lawn disease and fungus

    Brown patch, dollar spot, anthracnose and winter fusarium all show up as a patch of dead or discoloured turf. Mix them up and you end up treating the wrong disease at the wrong time of year.

    Signs that point here

    • Small, bleached, coin-sized spots that merge into larger dead patches
    • Circular brown or tan patches that expand fast in warm, humid weather
    • Irregular yellow-to-brown blotches on turf that is already stressed
    • Reddish-brown or orange patches that appear in cool, wet weather

    Read the lawn disease and fungus guide

If it is not one of those

Quite possibly it isn't. There are more causes of a bad patch than there are guides here, so these are the next places to look:

Three things worth doing before you treat anything

  1. Work at the edge of the damage, not the middle. Whatever is causing it is still active where the turf is half healthy; the dead centre has nothing left to tell you.
  2. Measure the area you are treating. Every label rate is per 100 m², so an unmeasured lawn is an unmeasured dose. The plan builder steps you through working it out.
  3. Read the label you are holding. Anything published here or on a product page is only a guide, and the label is the authority on rate, timing and re-entry.

Rather not diagnose it every year?

The Lawn IQ plans schedule feeding, watering and protection against your region and season, so the conditions that let problems start are handled before they do.