During the start of the spring season, it is not uncommon to get a call here and there from homeowners who may be wondering what type of weed is growing in their otherwise healthy lawn. Particularly in the early spring, the odds are good that the weed is is poa annua. This grassy weed is also known as annual bluegrass.
This common winter annual weed is found in local lawns during the spring each year. It typically germinates in the fall after the start of spring rain. Its lighter green color and prolific seed heads make it easy to spot, especially in dormant warm-season lawns like Bermudagrass or Zoysiagrass. Still, poa annua can be found in Fescue, too, which is what the lawns here in the greater St. Louis area tend to be.
How do you control poa annua in Fescue?
If you have Zoysiagrass or Bermudagrass, pre-emergent herbicide applications in the early fall, before the poa annua germinates, will form a barrier in the soil to prevent any seedlings from breaking through. However, Fescue lawns are not a good candidate for a fall pre-emergent application. Don't despair though! There is good news for Fescue lawns too! As long you overseed your lawn each year so that you can maintain a thick, healthy turf, poa annua tends to be less apparent than it is in the brown, dormant warm-season lawns.
Another option to control poa annua that has already germinated is post-emergent herbicides. These are liquid products that are designed to help kill existing annual bluegrass clumps. It is important to point out that post emergents will not prevent new clump of poa from popping up in your lawn. The efficacy of these kinds of weed control products is temperature-dependent. In warmer temperatures, plants become more active. When you treat an active the plant, it will uptake more herbicide. Makes sense right? I feel like we all tend to move a little slower when it is cold.
The good news about poa annua
There is a bright side here. Although we may have cold winters and chilly fall weather here in Missouri (conditions that tend to help poa thrive), we also get lucky with hot summers. Usually, once temperatures reach the 80’s or above consistently, poa begins to naturally die off on its own.
The other good news is that if you are a Loyalty customer, we will continue to do everything in our power to prevent and control annual bluegrass. before it becomes a problem. Take our consistent fertilization and weed-control programs and combine them with your proper mowing and watering; together, we will keep poa in its place.
Concerned about poa annua in your lawn? That's what we are here for! Don’t hesitate to reach out to your Route Ambassador or our friendly customer service team. We are here to Help Happy Grow!