Jack's Classic Acid Special Fertilizer, 4 lb. Perfect for greening up all acid loving garden and house plants. Feeds through both the roots and the leaves. Jack's Classic Acid Special 17-6-6 is very effective in reducing the soil pH, which keeps iron and other trace elements available to the plant. In plantings next to the concrete foundations of the home, where the pH is elevated, a root drench will keep the leaves green and healthy, promoting lush vegetative growth and better blooms. This formula contains elevated levels of iron and sulfur, which most of the acid loving plants require. Jack's Classic Acid Special is designed to lower pH quickly and effectively as well as deliver a balanced nutrient package for optimum plant growth. Application with Acid Special will be more effective than using the same plant leaves. The acidifying power of 17-6-6 is approximately 1,600 lbs. calcium carbonate equivalent acidity-compared to the only 1,000 lbs. equivalent acidity for most other common "acid" fertilizers. Only a few applications will be needed to effect the needed pH change. It can also be used to correct the iron-deficiency, chlorosis, which causes yellowing in acid-loving plants. Use of this formula should be limited to temperature ranges that do not fall below 45 degrees Fahrenheit.