Hydrangeas are deciduous shrubs that can provide elegant flowers to any Southern garden during the summer months. There are numerous varieties and types of hydrangeas with ranges of colors. Though there are too many varieties to mention, you can generally looks at hydrangeas in three groups, Hydrangea macrophylla, Hydrangea quercifolia, and Hydrangea paniculata.
Hydrangea macrophylla include ones commonly called bigleaf, mop head, lacecap, and French hydrangeas. The big-leafs are among the most common of the hydrangeas. The flower color of this group of hydrangeas can be changed to blue or pink depending upon the soil pH. Soil pH is responsible for changing the flower color in that it affects the aluminum uptake available for the plant. Acidic soils produce blue flowers (soil pH: 5 to 5.5), while alkaline soils produce pink flowers (soil pH: 6 or more).
Hydrangea quercifolia are known as the oakleaf hydrangeas. Oakleaf hydrangeas provide a showy display of white flowers and have leaves that are similarly shaped to an oak leaf. Oakleaf hydrangeas not only provide an attractive flower display in the summer, but also provide in interest during the other seasons through fall foliage color, leaf texture, and attractive bark. Some oakleaf hydrangea varieties include: ‘Snow Queen’, ‘Snowflake’, and ‘Harmony’.
Hydrangea paniculata is a group called PeeGee hydrangeas. PeeGee hydrangeas can be 10 to 25 foot tall. Instead of ball-shaped blooms, PeeGee hydrangeas have panicle-shaped blossoms. The blooms are also known for developing a pink shade as flowers age into the fall.
When it comes to growing hydrangeas, they are fairly easy to grow. Hydrangeas will grow 4 to 12 feet depending upon the variety. The growth rate of hydrangeas is quite fast. When selecting a site to plant hydrangeas, select a site that has well-drained soils. Hydrangeas do well in soils with plenty of organic matter. Hydrangeas do well in a location with morning sun and afternoon shade. They should not be planted hot, dry locations. Many think about purchasing and planting hydrangeas when they see them blooming in the summer, but spring and fall is the best times to plant.
Hydrangeas do well receiving small amounts of fertilizer throughout the growing season. A complete fertilizer, such as 10-10-10 applied at a rate of 2 cups per 100 square feet in March, May and July works well for hydrangeas. It is not necessary to remove the mulch when fertilizing, but water soon after application to help dissolve the fertilizer and send it into the soil.
Jessica Strickland is an Agriculture Extension Agent, specializing in horticulture for North Carolina Cooperative Extension in Wayne County.