Ideal Range

• Soil with a pH between 6.6 and 7.3 is considered neutral. Anything lower is acidic, and anything higher is alkaline. Blueberries prefer acidic soil, with an ideal pH range between 4.5 and 5.0.
  
  

Problems

• You can get a soil test done to determine the pH, but plants have their own way of telling you when something is wrong. Iron deficiency is the most common problem in blueberries growing in high pH soil. Iron-deficient trees display smaller than normal leaves that are yellowish with prominent green veins, often with brown edges.
  
  

Solutions

• Oregon State University recommends using one of two materials to acidify soil: nitrogen fertilizer and elemental sulfur. Of the two, elemental sulfur acts more quickly.