Easy instructions from the Allen County Extension Service
(Link to their website from PSE?’s website!)
Late March/early April - crabgrass control with little or no fertilizer
Early to mid-May - slow release fertilizer application. Broadleaved weed application if there is a problem
Late June/early July - preventative grub control if desired
Late August/early September - fertilizer; weed control if necessary
October - fertilizer