How to Speed Up Acidification of Soil for Blueberries

Add water to ¼ cup soil until it becomes the consistency of play dough. Form a ball with the moist soil. Use soil from the area where you will plant the blueberries.

Place the soil ball on a smooth surface and roll it out with your hands. Make a narrow band of soil 1/16-inch thick.

Measure the length of the soil band. Variations in length occur depending on how much clay the ground has. The amount of clay present determines how mulch elemental sulfur is necessary to acidify the ground.

Figure out how much elemental sulfur you need to incorporate into the soil based on the length of the soil band. Use the following rates as a guide: If the soil band is 1 inch long, apply 10 to 20 lbs. elemental sulfur per 1,000 square feet. If the band is longer than 1 inch, up to 3 inches, apply 20 to 40 lbs. elemental sulfur per 1,000 square feet.

If the soil band is longer than 3 inches, apply 40 to 50 pounds elemental sulfur per 1,000 square feet. (See References 2, page 5)

Rototill or spade the ground to a depth of 12 inches. Spread the elemental sulfur on the loosened surface. Incorporate it into the soil uniformly in the fall. Ideally, repeat this treatment one year later and test the pH the following spring. The earliest you should plant blueberries is 18 months from the first treatment. To speed up the process, go to step 6.

Plant the blueberry shrub the spring after you amend the soil with elemental sulfur for the first time. Dig four 1-foot-deep holes with 4-inch diameters around each blueberry plant. Use a trowel instead of a spade to keep the holes narrow. Make them below the drip line--the reach of the plant's outermost branch--and space them uniformly. Reserve the topsoil you dig.

Mix ¼ cup elemental sulfur with the reserved topsoil.

Refill each hole with the elemental sulfur mixture. Water the shrubs to release the amendment into the soil.