Shaun from Braselton, Ga writes
You may notice signs of the poa dying (discoloration-yellowing or browning) within 2-3 weeks after you have applied Certainty but it is normal not to see anything for at least a month. Per the product label, you can make an additional application 4 or more weeks after the initial application as needed. Best results are obtained when target weeds are actively growing & not disturbed by mowing for at least 2 days before and 2 days after application. Warm, moist conditions following application will accelerate activity; cold, dry conditions will delay activity. Drought stressed weeds are less susceptible.
Answer last updated on: 02/25/2019