Raising the pH involves adding lime to the soil. Lime can be purchased from garden centers or farmer co-ops. The amount of lime to add to obtain a particular pH is determined from a soil test in which a buffer pH is determined and then the amount of lime needed can be calculated.
Generally, pines do well in acid soil where the soil pH is between 5.5 and 6.5. If the soil is very acid (less than 5.5), it may be beneficial to add lime to raise the pH to about 6.5. Most nutrients are soluble in the soil and available for plant growth at a pH of about 6.5.
Contact your local Extension office and ask about soil testing services.
