You have a nice, thick, healthy looking cover of turf grass.
We don't think that you need to spray anything.
We think what you have there is Poa annua, or annual bluegrass, which 'blooms' early. With mowing it will be indistinguishable.
It may die back in the heat of summer. If it leaves any bare spots they can be overseeded in the fall.


Christine

Actually, sorry, I do have one more question. I sprayed my lawn with Prodiamine 65WDG at a rate of 0.9375 lb/acre. With such a large outbreak of Poa Annua/Annual Bluegrass (assuming it's that) do you think I may have put it down wrong? My understanding I that it should prevent most seeds from germinating.

Thanks!

Eddie

Hi Eddie,

When did you apply the Prodiamine? Annual Bluegrass is a winter annual, so it germinates in late summer or autumn, overwinters, and finishes maturing and going to seed in spring (which is what you're seeing now). Come summer, the bluegrass will die off on its own, so there's not need for a post-emergent follow-up treatment.

Pre-emergent herbicide to prevent the germination of the next generation of Annual Bluegrass needs to be applied at the end of the growing season (roughly late August or September). Spring applications of Prodiamine should work to prevent crabgrass germination and other summer annual grassy weeds, but it won't impact the winter annual weeds like Annual Bluegrass as it's already well-established by that point.

Miri

Hello Miri,

I applied a 5 month coverage of Prodiamine 3/06/2022. If I saw the annual bluegrass in this May, doesn't that mean it germinated this Spring (which means my application of Prodiamine 2 months ago should have prevented it from germinating)? Or is it more likely that it germinated last Fall, and I just didn't notice it until this Spring?

Thanks!

Eddie

Annual Bluegrass only produces seeds at the end of its life cycle, which occurs in spring. The seeds germinate later that autumn. Established plants were already present (even if not noticed) by the time you applied the pre-emergent, so they would not have been vulnerable to its effects. The herbicide's label does advise "in areas where Poa annua is a winter annual, apply Prodiamine 65WG...in August or September to established, non-overseeded turf before Poa annua seeds germinate." September is probably the ideal timeframe for application in Maryland.

Miri

You're welcome.