It?s best to feed mango trees with organic blends, since the tree is highly sensitive and prone to fertilizer burn. Apply three times yearly ? spring, summer and fall ? by spreading an equal amount out to and around the dripline of the tree and watering well. Meeting the mango tree?s preferred cultural requirements like proper sun, soil and air circulation, goes a long way in preventing disease problems. Keeping the foliage, flowers and fruits dry by irrigating around the base of the tree, also helps prevent problems, as does keeping the area beneath the tree cleaned of fallen debris and fruit.