LawnSuite guide: Couch mite: witch's broom on couch lawns
Use this LawnSuite guide to recognise the problem before deciding what to do. Couch mites are far too small to see without magnification. You usually spot them by what they do to the grass: short, bunched-up growth along the runners, often called witch's broom.
How to spot it
On couch, the mite causes a mass of short shoots bunched together at each node of the runners, a 'witch's broom', and the runners root poorly. Individual shoots can look shortened and thickened.
Hard to confirm by eye
Mites are tiny, mostly under 1 mm, and other mites can cause similar distorted growth on couch. Damage tends to be patchy, with hot spots, and it's easy to mistake for dry-weather stress.
When it shows up
Mites are most active in late spring and summer.
Your grass type
This mite is a problem on green couch. Zoysia is affected by a different mite, with different symptoms.
Lawn care that helps
Mites spread via grass clippings and wind. Laboratory studies found high mite mortality below about 80% relative humidity; dry ridges and areas missed by irrigation showed more visible damage. Clean your mower before moving from an affected patch to the rest of the lawn.
If you use a product
Mites aren't insects, so a product labelled only for insects may not control them. If you use a product, choose one whose label lists the mite and your turf type, and follow the label.
Keep reading
Sources: Australian government and university pages, summarised in our own words.
Keep track of it
Create a free LawnSuite account in your browser and log what you see and what you do, zone by zone.