Question
I live in central Wisconsin.  September 2008 I put down a quality seed for a new lawn and used a starter fertilizer(about half the recommended rate). For weeks beforehand I had been spraying Roundup to kill everything.  Mid October I put down the other half application of starter fertilizer as had been recommended to me and it appeared that it might have burnt the new lawn a little bit in some areas. This spring I would like to put down more seed to fill in some thin areas but I am also thinking about putting down a crabgrass preventer because I was killing a lot of grabgrass before I put the original seed down.  Is it best to put more seed down this spring and try to get a more lush lawn?  Or put down a grabgrass preventer this spring and seed in fall?

Answer
Hi Phil,

This is kind of a judgement call on your part. How thin and pervasive are the bad spots? If they are truly just thin, and not bare, then I'd recommend fertilizing with a Crabgrass preventer + fertilizer. The food will get the lawn growing and filling in by itself, and the crabgrass preventer should prevent you from a repeat performance this season.

Please take care to make sure you know how to use your spreader well too. If you are using it properly, burned spots should not be an issue. I often recommend that people practice with some pelletized limestone before using the real fertilizer. The limestone is cheap and spreads similarly to the fertilizer. You can get a good feel for how to do it before you risk any more mistakes.

Good luck Phil!

-C.J. Brown
www.TheLawnCoach.com