Apply fertilizer high in nitrogen to mature fruit trees
Most mature fruit trees (5 years and older) require the equivalent of one-pound of actual nitrogen annually. One pound of nitrogen can be supplied with 5 pounds of ammonium sulfate (21% N), or 8 pounds of blood meal (13% N) Divide the amount of fertilizer required for one year into three equal lots and apply them six weeks apart, starting in the spring after new growth begins.