This is a low salt, slow release, professional grade horticultural fertilizer that uses different nutrient sources to ensure a constant release rate. This is a perfect fertilizer blend for all varieties of Crape Myrtles and blooming trees. NutriStar for Crape Myrtles should be applied early in the spring at full rate. Subsequent applications should be made every 60 days at half rate to achieve the best results. Includes ureaform, monoammonium phosphate, potassium nitrate, potassium sulfate – magnesium, triple super phosphate, sulfur, magnesium oxide, ferrous sulfate, magnesium sulfate, calcium sulfate, sulfur, zinc sulfate, manganese sulfate, copper sulfate. Great for: Crape Myrtles, Flowering Pear, Crab Apple, Mexican Plum, Orchid Tree, Vitex, Mimosa, Desert Willow, Texas Mt. Laurel, Viburnum. 10-15-9 , 4lb. box.