One of the most popular flowering shrubs for sale, hydrangeas offer large flower heads in shades of pink, blue or purple. A variety of hydrangea types are available including oakleaf, panicle, macrophylla and serrata. Hydrangeas can be planted as accent plants, foundation plantings and flowering hedges. When selecting hydrangea bushes for sale, make sure they are suitable for your grow zone. Also, pay attention to their light requirements. While some hydrangeas like full sun, others prefer more shade. Some hydrangeas change flower colors, depending on the soil pH. The flowers become bluer in acidic soils and more pink in alkaline soils. Also note the hydrangeas mature height and spread.