The majority of garden plants prefer a soil pH of 6-7, but….

Certain common plants require acidic soil (pH UNDER 7) including: azaleas, rhododendrons, blueberries, butterfly bush, blue-flowered hydrangeas, camellias, dogwoods, heathers, magnolias, pines, spruces, and yews. While these plants may survive in soils with a higher pH, they grow and bloom best in soil with a pH of 4-5.5.