Is winter grass the same as Poa annua?
Quick answer
Yes. Winter grass is the common Australian name for Poa annua, a grass weed also called annual bluegrass or simply poa. It germinates in autumn, grows through winter and seeds in spring. Product labels may use either name, so look for winter grass or Poa annua when checking whether a product covers it.
Why this happens
Winter grass and Poa annua are the same plant. “Winter grass” is the name most Australians use, because that’s when it’s obvious in warm-season lawns. Turf professionals often just call it “poa”, and overseas it’s called annual bluegrass.
The scientific name matters when you’re reading labels and research. A label might list “winter grass (Poa annua)” or only one of the two names. Either way, it’s the same weed.
Knowing the name also helps you avoid confusing it with ryegrass, which some people sow in autumn for winter colour. If you didn’t sow anything and pale tufts with whitish seed heads appear through winter, it’s almost certainly winter grass.
How to tell winter grass from ryegrass
Some people sow ryegrass in autumn to keep a lawn green over winter, and the two can look similar from a distance.
- Colour: winter grass is usually a paler, lighter green than the lawn around it. Ryegrass tends to be a darker, deeper green.
- Seed heads: winter grass produces small, whitish, open seed heads at mowing height through late winter and spring. Ryegrass seed heads are long, flat spikes, and in a regularly mown lawn you rarely see them.
- Where it grows: winter grass appears in scattered tufts and in thin, damp or compacted spots. Sown ryegrass is spread evenly across the lawn.
- History: if nobody sowed anything in autumn, it’s very likely winter grass.
Why the name matters
Product labels list the weeds they control. When you’re checking whether a pre-emergent or selective herbicide covers your problem, look for “winter grass” or “Poa annua”. If neither appears in the weeds controlled, the product isn’t registered for it.
Is it always annual?
Most winter grass in home lawns behaves as an annual: it comes up in autumn and dies back in summer. Some types can persist as perennials in some turf situations, which is one more reason to stop it seeding.
What you may be seeing
- Soft, light-green grass in tufts
- Whitish seed heads in late winter and spring
What you can do
Check the plantCheck first
Compare it with the photos and features on the winter grass Lawn Library page.
Check product labels for either nameCheck first
Labels may say winter grass, Poa annua, or both.
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.
What's next
Related grass types, weeds, pests and diseases
Weeds
Related questions
Related guides
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Sources
- Turf weed, pest and disease identification guide (poster), Bayer Environmental Science, hosted by Turf AustraliaWinter grass (Poa annua). Accessed 3 October 2026.