Make sure your trees are healthy and green all season long with Ross® Root Feeder Refills Green Again with Iron. Chlorosis, a yellowing of the leaves with green veins, is caused by a lack of iron in your plants diet. Use Refills in your Ross Root Feeder to get the perfect balance of nutrients directly to plants roots - while watering too. With other fertilizers, you dont know how much of the fertilizer is actually reaching your plant. These refills are a special formula of fertilizer plus iron for plants suffering from yellow-leaf iron deficiency. Apply when first symptoms appear or to prevent deficiency if chlorosis has been a problem previously. Ross premeasured refills make for fast, easy and mess-free fertilizing.