Hi , I fertilized in December and February mainly because I have absolutely no experience in this endeavor and am clueless . I am trying however . I am sending a soil sample to a lab tomorrow for a complete analysis . Maybe I'll learn something valuble . I am and will continue to be concerned with ' green-ness ' ... after all this is a Baseball field . I also spend a considerable amount of time and effort in striping it when I mow . Looks matter ... alot . ( to me anyway ) I am very interested in achieving a healthy , green ballfield by using the info that this forum provides . I am a bit ' behind the curve ' , but I'm a quick study :>) Thanks !! J.D.