An old Polish proverb says that “What you do now will determine what you must do later.” Today we’re applying that to the topic of weeds.
Generally, you can apply a pre-emergent in March and September. You must apply pre-emergent before the growth of weeds, because it will not kill existing weeds.
Pre-emergents are designed to prevent the seeds of weeds from germinating; therefore, you should use weed killer on weeds that are already present. As always, follow the manufacturer prescribed instructions and precautions. Better safe than sorry.
Application dates for applying pre-emergent can be different than your fertilizing dates, because you should apply fertilizer after your grass has come out of dormancy. If you apply a fertilizer that is high in nitrogen before the grass has a chance to grow, you inadvertently feed the weeds. Especially if you didn’t add a pre-emergent last fall to stop the seeds that are sprouting by this time. And now, we’ve gone full circle!
Until next time, Thanks so much!