Act now to control winter grass!

Author: Stefan Palm   Date Posted: 27 February 2024 

Did you know there is a herbicide you can apply now that will stop winter grass from germinating in the coming Winter? Sounds hard to believe, doesn't it? But you'll need to act quickly as there is an optimal window of time for its application.

Winter grass (otherwise known as Poa annua or annual bluegrass) is that annoying light green coloured grass that often comes up in your lawn during winter -  It's an annual weed, meaning it only lives for a short time and only comes up at a certain time of the year. The season for winter grass is typically from mid-April through to September, and with cooler days and nights coming soon, the germination of winter grass seed in your lawn is just around the corner. 

You’ll know exactly what I’m talking about if you have it. It produces lots of seeds and has a white cotton-like root zone. It’s easy to pull out, but there is always so much of it, and more often than not, as soon as you pull it out, more seems to grow back. One of the survival mechanisms of Winter Grass is its seed. It produces large amounts of it, which fall to the ground, ready to germinate next year. If each winter grass weed produced 50 seeds, and all of those seeds fell to the ground and germinated, you can see how quickly this weed could get out of control.

The big question is, how do you get rid of it, and how do you successfully keep it out? By far, the best way of controlling winter grass is with a pre-emergent herbicide.

Pre-emergent control

Wintergrass is best treated for now through a process called pre-emergent weed control. Pre-emergent control works on the principle that you control the weed's seeds before they germinate, therefore preventing the weed from taking its annual foothold. You can apply products such as Spartan that do exactly that, meaning you won't see it come winter.  

That in itself is amazing. If you’ve got a serious winter grass problem and you’ve been attacking it for a few years, you’ll know two things:

  1. It gets worse every year, despite your efforts to remove it
  2. Selective herbicides that you buy and apply during winter don’t necessarily solve the problem.

A pre-emergent approach seems counterintuitive in a way because it can seem like you’re treating a problem that isn’t there (yet); however, as you have probably gathered by now, you’re doing a form of preventative maintenance, and in that way, you’re stopping the weed before it becomes a problem.

When to Apply pre-emergent herbicides

The best time of year to apply Spartan is the months leading up to Winter before the weeds germinate – i.e. February to early April.  As soon as we get a couple of successive rains, combined with cooler weather, winter grass seeds will begin to germinate. It is critically important that this herbicide is sprayed before the weed emerges. In other words, if you can see winter grass growing in your lawn, then it is too late to apply this season. 

If you've been battling it for a few seasons, try Spartan. It is an absolute weapon against winter grass!


Comments (47)

Winter grass problem

By: on 29 July 2024
Hi , reading through these comments, it is too late for a pre emergent on Santa Anna. What is best for use now ?

Paul Munns Instant Lawn Response
Hi Andy, It is a bit late for a pre emergent now, you could use a post emergent to kill what has already germinated but it wont kill the seeds in the ground. Once the temperatures start to warm up the winter grass that you can see now will die off. You can apply the pre emergent in Autumn sometime around May. Thanks for your enquiry!

Winter Grass

By: on 18 February 2023
Hi Paul, is it safe to use Spartan on Windsor Green lawn. Kind Regards Cheryl

Paul Munns Instant Lawn Response
Hi Cheryl Thanks for your enquiry Yes, Spartan is safe to use on Windsor Green Couch Thank you Regards Andrew

Winter grass

By: on 25 March 2022
Hi We have couch and in winter it needs infrequent mowing. The dreaded Poa emerges and is very obvious, even before going to seed. Our lawn is only about 70m2 and I patrol it once every week or 2 and pull up up the invader. We had instant turf rolled out about 10 years ago and the first winter I literally pulled up thousands of Poa. You can tell I'm retired - too much time on my hands.

Paul Munns Instant Lawn Response
Hi Brendan Thanks for your message To prevent winter grass from germinating in Winter you can use one of two pre-emergent products we stock. We have Pendi Pro which is a fertiliser and pre-emergent in one or we have Spartan which is a pre-emergent by itself. These can be applied now as long as no Winter grass has germinated. Thank you

Winter grass

By: on 20 August 2021
Hi can you tell me is there any product l can use on tall fescue lawn to kill winter grass. Regards sue

Paul Munns Instant Lawn Response
Hi Sue Thanks for your enquiry Unfortunately there isn't anything selective to control Winter Grass in Tall Fescue lawns

Tall fescue and winter grass

By: on 12 August 2021
Hello, I see in the above comments there is no way to Control winter grass in tall fescue. Will winter grass die off after winter or should I be removing it as it appears? Or open to other suggestions.

Paul Munns Instant Lawn Response
Hello Mat Unfortunately there isn't anything selective to control Winter grass in Tall Fescue. I would recommend to get it all out (as much as possible) Winter grass will die off in the heat of Spring and Summer but will drop the seeds in the soil and germinate next winter Thank you

poa weed

By: on 5 July 2021
Paul - I have a santa ana lawn . Is it safe to use spartan in this lawn and when is it best used . Is it too late now

Paul Munns Instant Lawn Response
Hi Alan Thanks for your query Spartan is safe to use on Santa Ana. Best to apply it in Feb/March next year. Bit too late now Thank you

Is it pet safe

By: on 14 June 2021
Is this product pet safe and how long after application can pets return to the area

Paul Munns Instant Lawn Response
Hi James Thanks for your query Yes, it is ok to use if you have pets. I would just recommend to allow drying time of the product before pets go back on the area Thank you

Leave a comment

Comments have to be approved before showing up