Question
I ran an aerator over my yard and the spread a granule pre-emergent over the yard. I sprayed it with water and moistened soil, then raked it to sped the loose soil around next day. I want to seed it and spread some topsoil and then put down some hay. I was wondering how long I should wait after pre-emergent to do seeding? When is the best time to seed? I live in Memphis in case you need to know.  Also is there anything else I should do along with the seeding like lime or anything?

Answer
Hi Josh.

The pre-emergent herbicides are meant to last a full season. If they worked perfectly, you'd have no chance of getting good grass growth this year. If they wore off after two weeks or something like that, there'd be almost no point in applying them.

Luckily for you, they don't work perfectly. If you need to get some more seed into the lawn, then go ahead and do it whenever you have time. It won't grow as well as you might be hoping for, but you should see something reasonable. You should also see crabgrass and weeds growing in with the grass. As I said, the pre-emergent herbicides don't work perfectly.

In the future, the best approach is to do any seeding in the cool fall weather when the weeds aren't too aggressive, then just apply a pre-emergent in the spring to keep the weeds to a minimum. In other words, first grow the lawn, then prevent the weeds.

Good luck!

-C.J. Brown
www.TheLawnCoach.com