|I have aerated & overseeded 5 weeks ago. I put down Scotts turfbuilder for Southern lawns on 10/1/09. How long do I wait before putting down a pre-emergent? When is it too late to put it down?|
|The big question for pre-emergent weed killers is when to apply them. Pre-emergent herbicides only work if they are applied to your lawn before the weed's growth period. But if applied too early, weather will dilute the herbicide and the weed will grow unencumbered.
The two dates to remember are March 15 and September 15. Those are the two dates of the year around which pre-emergent fertilizers should be applied so that they activate before seasonal weeds make an appearance.
It's a little late for the fall application but you can make the early spring application to keep summer weeds from sprouting.
Your best defense against weeds is a thick, healthy lawn. It sounds as though you've done everything necessary to make your lawn healthy so a spring application of pre emergent should be all your lawn will need. Best wishes with your lawn!