I planted a yard last year. It seems that in the backtard the grass did not grow well as the guy who did it did not do so well with the tilling of weeds. Can I put Scotts crab and halt on first? IF so when do you know when to do it. I live in Minnesota. Then is it smart to put a fertilizer down in May? I am trying to find help on what I should do with my lawn as it is the first I have ever had to deal with. I would like to get a lush green yard. Any help would be greatly appreciated.