The Recommended pH Levels for Blueberries

Ideal pH for Blueberries

• When preparing a soil for blueberry cultivation, aim for a pH of 4.8. This doesn't have to be exact, but the pH shouldn't be much higher than 5.0, nor should it be too low. Overshooting and making a soil too acidic can result in stunted bushes.

Differences Between Types of Blueberry

• For rabbiteye blueberries, you should add sulfur to lower the pH if it is above 5.3. For highbush blueberries, add sulfur if the pH is above 5.0.

Using Wettable Sulfur Prior to Planting

• Wettable sulfur, which contains 90 percent elemental sulfur by weight, can be bought in any garden supply store. For sandy soils, applying 1 pound of wettable sulfur per 100 square feet should lower the pH by one, such as from 6.0 to 5.0. For thicker soils with more silt, clay and organic matter, it may take up to 2 pounds per 100 square feet for the same effect. Add sulfur at least three months before planting so it has a chance to mix in.

Selecting Mulch

• Applying a 3- to 4-inch-thick layer of mulch around the bushes after planting can help improve water drainage and keep the soil from getting too hot in the sun. If you decide to use mulch, use pine bark, chips, sawdust or needles instead of a hardwood mulch. Pine-based mulches have a lower pH and are therefore more suitable for blueberries.