How do I get rid of winter grass?
Quick answer
Stop it before it starts. Winter grass germinates in autumn, so a pre-emergent applied in autumn, before seedlings appear, prevents most of it. Plants already growing can be dug out before they seed in spring, or treated with a selective product whose label lists winter grass and your grass type. A thick, healthy lawn leaves less room for it.
Why this happens
Winter grass (Poa annua) is an annual grass weed. Its seeds germinate in autumn as days shorten and soils cool, the plants grow through winter while warm-season lawns slow down, and in spring they produce seed heads. One season’s plants can leave a lot of seed in the soil for next year.
That life cycle is the key to controlling it. Pre-emergent herbicides work on germinating seeds, so they have to be in place before winter grass comes up in autumn. Once the plants are up, a pre-emergent won’t kill them. At that point your options are digging them out, or using a selective post-emergent product whose label lists winter grass and your grass type.
The other half of the job is the lawn itself. Winter grass seedlings need bare soil and light. A dense, well-fed warm-season lawn going into autumn leaves fewer gaps, and fewer gaps means fewer winter grass plants. Thin lawns, compacted paths and damp, shaded areas are where it usually starts.
Is it worth spraying in spring?
Once seed heads are forming, killing the plant won’t remove the seed already shed. In spring it’s usually better to dig out what you can, catch clippings, and plan an autumn pre-emergent.
What you may be seeing
- Light green tufts of grass that stand out against your lawn from autumn onwards
- Small, whitish seed heads in late winter and spring, even right after mowing
- Patches that die off in late spring and early summer, leaving gaps
It depends on your grass and climate
| If you have… | What changes |
|---|---|
| Buffalo | Buffalo is sensitive to some herbicides. Pre-emergent and post-emergent products must list buffalo on the label. |
| Couch and kikuyu | More products list couch and kikuyu |
| Zoysia | Check the label lists zoysia; not every product does. |
| Cool and highland areas | Cool-season lawns (ryegrass, fescue) are grasses themselves, so many winter grass products don't suit them. Check the label. |
Rows that match the grass and climate zone you've set are highlighted. Set your climate zone
What you can do
Identify itCheck first
Make sure it's winter grass, not ryegrass you sowed for winter colour. See the Lawn Library page for the signs.
Remove what's there before it seeds
In small areas, dig out plants with the roots in winter, before seed heads mature. Catch clippings while it's seeding.
Thicken the lawn
Feed and water the lawn in the growing season and fix thin, compacted or shaded spots, so there's less bare soil next autumn.
Pre-emergent in autumnProduct step
Apply a pre-emergent whose label lists winter grass and your grass type, at the label rate, before germination in autumn. Water in or not exactly as the label says.
Selective spray for plants already upProduct step
Where the label lists your grass, a selective post-emergent can kill young winter grass. Follow the label for timing and rate.
What not to do
- Waiting until spring to act. By then it's seeding, and next year's crop is already in the soil.
- Using a product that doesn't list your grass type, especially on buffalo.
- Laying turf or sowing seed soon after a pre-emergent without checking the label's waiting period.
How much do I need?
A label rate of "20 mL per 100 m²" means: Rate 20, mL, per 100 m². Per hectare? Use 10,000 m².
How much you need
Enter your lawn area and a rate to see how much product and water you need.
Log it
Keep a record of what you applied, when, and at what rate. Your Lawn Journal works on this device without an account, and reminds you when the next step is due.
What's next
Related grass types, weeds, pests and diseases
Weeds
Related questions
Related guides
Common follow-up questions
Will winter grass die off by itself?
Yes, it usually dies back as the weather warms in late spring and summer, but by then it has dropped seed for next autumn. Removing or preventing it breaks the cycle.
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Sources
- Turf weed, pest and disease identification guide (poster), Bayer Environmental Science, hosted by Turf AustraliaGerminates in autumn, grows through winter, seeds in spring; pre-emergent in autumn before germination. Accessed 3 October 2026.
- Herbicide mode of action table, CropLife AustraliaGroup 3 pre-emergent actives. Accessed 4 October 2026.
- Search registered chemical products and permits (PubCRIS), Australian Pesticides and Veterinary Medicines Authority (APVMA)Check a product's registration and label. Accessed 3 October 2026.