Iron Combo Chelate Iron Combo Chelate™ is a broad spectrum micronutrient fertilizer containing natural, organic-based chelates of iron, zinc, manganese, copper and boron. It can be applied to lawns, trees, shrubs, greenhouse plants, flowers and gardens. Any plant with iron chlorosis or micronutrient deficiencies can be effectively treated with Iron Combo Chelate™. Greening can be seen within a week and can be maintained by additional foliar applications. Iron Combo Chelate™ is 100% biodegradable and can be used as an energy source by the plant.