since we live in diff. areas, this may not apply. Here its Bluegrass, so my (old) program was..
Spring App... Fert w/ iron
Dursban(surface rate) told ya it was old program...lol
Early summer app....Fert w/iron
Barricade(1/2 rate app)
weed control as needed(trimec)
Summer app.... Fert w/iron- slow release N
weed control as needed and as weather permits...spot spray....
Fall app.... Fert w/ iron
Grub control in late July....Merit...used Triumph as a curative.
Late Fall fert. late Oct. or Nov.
For Fert. went with the 1lb./1000 N, about 1/4lb. potassium and potash. Good source of info for me was Iowa State Agronomy Dept. Lotta help for commercial lawn care owners.. just my 2cents worth.