I am using a 34-3-11 witch is a slow release fert. you dont get all the Nitro all at once,maybe over a 4 month peroid.It kind of depends on your appl. rate how much? 1/2 pound/thousand sq.ft. probably wont do any thing but give it a jump.I was tought at E.K.U. that 1-2pd/tho.sq.ft.in the spring and up to 5 pd.tho sq.ft.in the fall.But you do definitely need the slow release.