So it's definitely a good idea to get started well ahead of the intended planting time. The amount of sulfur to use will depend on the soil's initial pH and its texture, and ranges from 1 to 7 pounds per 100 square feet. Ask the testing service that will analyze your soil samples—the state agricultural extension or a private lab—for recommendations, based on your specific soil conditions, for growing blueberries. Mix the recommended amount of sulfur into the upper 6 inches of the soil in the area where you will plant the blueberries.
Originally published in Organic Gardening Magazine, Oct/Nov 2013