Overseeding and Crabgrass preemergent
We're now in April in New England and next week my lawn guy will be doing his power raking as part of his spring cleanup.
My question is this: I would like to lay down some perennial ryegrass overseed as my lawn was thin last year.
I have a contract with a lawn service and they are set to apply their step 1 fertilizer which has crabgrass preventer. I asked if the crabgress preventer will kill my new seeds, and they said I should be OK, as long as my new ryegrass seed has had two weeks to germinate...Is this right?
Obviously, I don't want to lay down a bunch new seed today, and have it germinate, only to have my pre-emergent laid down two weeks later and kill it.
Re: Overseeding and Crabgrass preemergent
In my experience, 2 weeks is cutting it way too close. I usually wait until I've mowed the lawn at least twice (probably closer to 4-5 weeks). They do make crabgrass preventer / fertilizer that uses a different type of herbicide what allows you to seed and treat at the same time, but it's usually 3 times more expensive than the usual stuff.
What I typically do in your situation is use your basic starter fertilizer without crabgrass preventer to feed the seedlings then use a post-emergent liquid herbicide to kill any sprouted crabgrass.