Annual Bluegrass (Poa Annua)

Poa annua can be a frustrating weed to have in your lawn.  It is usually a lighter shade of green than surrounding turfgrass, and isn’t as hardy.  Because it doesn’t stand up well to disease, traffic, or drought, having poa annua present in your lawn often leaves you with brown sickly looking patches.  Even though it can be tough to get rid of, there is hope!

There are two options when trying to eradicate poa annua.  Since it’s an annual, you can use a pre emergent herbicide to prevent it’s seeds from sprouting.  Or you can use a selective herbicide that will kill the poa annua, but leave desirable grasses.  I recommend using both methods for the best control.

If you opt to use the pre emergent, make sure to apply in late summer/early fall.  This is when most of the poa annua seeds will begin to germinate.

If you decide to use a selective herbicide, I recommend Tenacity.  It is safe for use on Kentucky bluegrass, tall fescue, fine fescue, and perennial ryegrass.  It may take more than one application to kill the poa annua.  Patience is the key.  You are going to want to wait 3-4 weeks between applications.  If your lawn is heavily infested with poa annua, keep in mind that you may need to seed some thin or bald spots after the herbicide treatment.


Leave a Reply