Why do you need so much fertilizer? If it's cool season grass (fescue,
bluegrass, rye) it only needs 1 lb. of nitrogen per 1,000 sq. ft. in the
spring/summer. Over fertilization leads to brown patch and other cute
diseases.

Now it you have warm season grass (bermuda, zoysia, St. Augustine, etc.)
that's a different story. What kind of grass *do* you have?

Chris wrote:
I am located in zone4 and just core aerated the lawn. I put fertilizer down
about two weeks ago then sprayed with a liquid weed killer Ortho- Weed -
Bgone. Is it ok to fertilize the lawn again so soon ? I would like to put it
down while the soil is opened up.