How to Identify and Treat Winter Grass (Poa annua)

“One year of seeds brings seven years of weeds!” – This could not be any truer than when it comes to the fight against Winter Grass in your turf.

If you have an invasion of Winter Grass, you’ll definitely want to treat it before it goes to seed. If you allow it to drop its seeds, next winter it will be back, twice as bad as it was the previous year. Best plan of attack is to treat it as soon as it appears or better yet, apply a pre-emergent like Oxafert and Oxafert Plus to stop it germinating at all.

What is Winter Grass?

Winter Grass, or Poa annua as it is scientifically known, is a low growing weed. It has soft, drooping green leaves grown in tufts with triangular shaped seed heads.

When does it appear?

This weed begins germinating in the soil in some areas as early as March. You will start to see it emerging within your turf as the temperatures begin to decline. It will continue to spread throughout the Winter months.

How do I get rid of Winter Grass?

This weed can be removed very easily by hand as it doesn’t have particularly deep roots. It doesn’t have any runners and will grow in simple clumps. Removing it by hand can be somewhat tedious so fortunately there are specifically targeted herbicide controls you can use.

Winter Grass Treatment

Winter Grass Killer is a selective control that will kill Winter Grass by targeting the roots, so it is extremely important to spray early in its life cycle before seed heads appear. Munns Winter Grass Killer is another option that is safe to use on kikuyu lawns. For cool-season lawns like Rye and Tall Fescue, Nominee Herbicide is a safe option.

How Do I Prevent Winter Grass?

Targeting it before it emerges is the key to preventing it from germinating and going to seed. A pre-emergent like Oxafert can be applied and it will target the Winter Grass before it emerges from the soil.

Once it goes to seed, they will be present again in your turf the following year and the cycle will continue. Using a combination of a pre-emergent like Oxafert and a selective control like Winter Grass Killer at the correct time of year should ensure it is eradicated from your lawn.

If liquid lawn care products are more your style, Barricade Pre-Emergent Herbicide is another pre-emergent option to consider.

If you have a cool-season grass like Rye or Fescue, a safe pre-emergent option is DithoMax.