Poa Annua (Annual Bluegrass)
A winter annual grassy weed that germinates in fall and winter, produces light green clumps in your lawn, then dies as temperatures rise in late spring — leaving bare patches. It is the primary target of fall pre-emergent applications.
Poa annua (Poa annua) is one of the most persistent lawn weeds in the country. It germinates in fall (unlike most weeds that germinate in spring), grows through winter as light-colored, light green clumps, flowers in early spring, then dies as temperatures rise — leaving dead patches just as your lawn is trying to look its best.
Prevention: A fall pre-emergent applied in August–September is the best control. Prodiamine and pendimethalin both work.
Challenge: Poa annua produces hundreds of seeds per plant each year and those seeds remain viable in the soil for years. Consistent fall pre-emergent applications are needed to reduce the seed bank over time.
More on Pre-Emergent
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