Act now to control winter grass!
Author: Stefan Palm Date Posted: 26 February 2025
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:
- It gets worse every year, despite your efforts to remove it
- 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 (53)
Pre-emergenct for cool season grasses
By: Jack on 3 March 2025Hi there! I have a lawn which is made up of annual/perennial rye, RTF tall fescue and Kentucky Bluegrass. Is there a pre emergent that is safe for these types of grass? Had to do a couple of sprays over summer this year with DSMA for paspalum and crows foot and would prefer to get on top of it all during the year. Cheers!
Paul Munns Instant Lawn Response
Hi Jack, it's difficult to say sorry! The pre emergent we sell here (Spartan Herbicide) isn't labelled for use on cool season grasses such as rye, fescue, and bluegrass. This means the manufacturer hasn't tested the chemical on those specific varieties, so we can't be sure whether it will damage them. It might be worth having a hunt around for a pre-emergent that is labelled for cool season grasses, otherwise you could try applying Spartan to an inconspicuous part of the lawn and observing if any damage occurs. If you have any questions, please give us a call on 8298 0555.
Puppies & Spartan
By: Cherie Pitcher on 28 February 2025Is Spartan dangerous to puppies?
Paul Munns Instant Lawn Response
Hi Cherie, you can use Spartan on your lawn if you have puppies. I definitely wouldn't let them get into the bottle, but Spartan is an unscheduled chemical. It's much less toxic than some other chemicals commonly used on lawns. I'd recommend watering Spartan in immediately after application and keeping the puppies off until the spray has dried. Thanks for your enquiry.
Spartan and dogs
By: Lesley on 28 February 2025Is it safe to use when you have dogs?
Paul Munns Instant Lawn Response
Hey Lesley, Spartan is safe to use if you have dogs. I certainly wouldn't let them get into the bottle, but it's an unscheduled chemical, meaning it's much less toxic than other herbicides regularly used on home lawns. I'd recommend watering Spartan in immediately after application and waiting for the spray to dry before allowing the dogs back onto the lawn. Thanks for your enquiry.
Spartan preemergent
By: Paul on 25 February 2025Hi can I use Spartan on Santa Ana couch? Cheers!
Paul Munns Instant Lawn Response
Hi Paul, yep! Spartan is safe to use on Santa Ana couch. Thanks for your enquiry.
Matilda buffalo
By: KB on 14 December 2024Hi guys I had winter grass this year for the first time, what a pain to pull option all out. To read that it will most likely come back gives me chills
Paul Munns Instant Lawn Response
Hi, yep it is certainly a persistent weed! Correctly applying a pre-emergent such as Spartan will prevent it from popping up again, so it's definitely worth looking into to save pulling it all out by hand.
Bow and arrow
By: Celette on 9 October 2024Can I use Bow and Arrow on my Windsor Green now (october) and then Spartan in april
Paul Munns Instant Lawn Response
Hi Celette, Bow and Arrow can be applied now to control broadleaf weeds, but it doesn't kill wintergrass unfortunately. Spartan can be applied in April as long as you haven't started seeing any wintergrass at that time. Thanks for your enquiry!
Winter grass problem
By: Andy on 29 July 2024Hi , 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!