Plants that thrive in acidic soil include bleeding heart, foxglove, heather, azaleas and rhododendrons. There are also several fruit and vegetable plants that need acidic soil to grow such as radishes, peppers, rhubarb, blueberries and currants.
Some plants not only thrive in acidic soil, but need it to grow properly. For hydrangea blossoms to turn blue, the soil needs to have a pH between 4.5 and 5.5. Both foxglove and bleeding heart require slightly less acidic soil at a 5.5 to 6.5 pH. Azaleas and rhododendrons aren't picky about the acidity level as long as it is between 4.5 and 6.0.
Some vegetable plants need acidity to survive such as potatoes, sweet potatoes, radishes, peppers, rhubarb and parsley. These plants need a pH generally between 4.5 and 6.5, although potatoes grow best with a pH between 4.8 and 5.5. However, these plants can adapt well to alkaline soils. Vegetables such as broccoli, beans, tomatoes and turnips can tolerate acidic soil. Berries thrive in acidic soil or at least tolerate it. For instance, blueberries, cranberries, elderberries, gooseberries and currants all need a soil pH of 6.5 or lower. Raspberries and strawberries can tolerate acidity as long as the pH is above 5.5.