I was told for a Bluegrass lawn in Wisconsin you need about 6lbs of Nitrogen per season. I think we all agree that about 2/3 rds of that needs to be put down in the Fall (late AUG). The other 1/3 in the Spring (April) . If my 50lb bag says 25-3-5, and covers 12,500 sqft. That would be 4 lbs of fert per 1,000 sqft, right? Or 1lb of N per 1,000 sqft. Ok, here is the big question. When and how many times do you put down fert? Pre-merg for grassy weeds? Broad-leaf control?