Espoma Tree Tone and Dr. Earth's Natural Wonder are two effective natural fertilizers for apple trees. Both products are formulated for use in organic gardens.
Espoma Tree Tone provides the necessary macronutrients to trees including 6 percent nitrogen, 3 percent phosphorous and 2 percent potassium. More than half of the nitrogen in Tree Tone fertilizer is released slowly over time. The formulation includes small amounts of magnesium and calcium. Espoma blends its fertilizers with a trademarked blend of beneficial microorganisms called BioTone.
Dr. Earth's Natural Wonder includes 7 percent nitrogen, 4 percent phosphorous and 2 percent potassium. In addition to minerals, the fertilizer also provides the proprietary ProBiotic blend of beneficial microorganisms.