HI-YIELD AMMONIUM SULFATE is one of the best available forms of Nitrogen and Sulfur. Ammonium Sulfate, a quick-acting source of Nitrogen, helps to give green color to plants and promotes rapid growth. Sulfur, an essential element of soil fertility, helps to acidify the soil and promotes stronger plant growth. *Recommended for growing Blueberries and Potatoes!*. Apply HI-YIELD Ammonium Sulfate throughout the growing season. Water generously and promptly following application. N-P-K: 21-0-0. Flowers & Vegetable Gardens: Apply 1/2 pound per 100 sq.ft. evenly or 1 teaspoon per plant, avoid the stem and water immediately. Shrubs Including Evergreens and Acid Loving Plants: Apply 1/4 cup evenly under plant near the drip line, avoiding contact with the stem. Water immediately. Trees: Apply 1/2 pound per inch of trunk diameter, spread evenly under the drip line and water heavily. Blueberries: HI-YIELD AMMONIUM SULFATE is the preferred choice to fertilize blueberries when the soil pH IS above 5. Evenly spread within 12 to 18 inches of the plant, not directly to the stems or crown. Apply 2 to 3 Tbsp per plant on plants that are under 4 years old. On plants older than 4 years apply up to 8 Tbsp per plant. Make applications in April, May and June, or only in May and June if farther north. Compost Piles: Apply 1-2 pounds per 10 sq.ft. to each 6-inch layer and water in.