I've had my Marathon I sod lawn (tall fescue) for only about 6 months, so I'm new at lawn care and can only tell you what has worked for me in my limited experience. I have sandy soil and my lawn gets SW exposure (full-time blasting sun). I first started fertilizing my lawn 3-4 months after planting it, using ScottsWinterizer fertilizer because it was late fall and I could buy it inexpensively at Home Depot. I thought it worked pretty good, but My sprinkler guy recommended Bandini Supergreen for winter fertilization. My lawn was yellowing aboout a month or two after application of the Scotts, so I tried the Bandini Supergreen (Sadly, I had to get it at Green Thumb Nursery because Home Depot doesn't carry it). All I can say is WOW! The stuff must have green dye in it because my lawn greened up in a week or two and a month later it's still green. But I have heard people say that you don't need to fertilize your lawn if you use a mulching mower. My yard care person thinks that mulching mowers cause thatch and are the devil incarnate, though, so I haven't tested this. I am getting my own mower for other reasons and will probably get one with a mulcher just to have the option, if not use it all the time.