When my parents moved houses last year, their new residence had a number of hydrangeas established in the landscape. They aren’t my mom’s preferred plant, so this spring they dug them out and gave them to me. I was concerned that they were going to struggle with transplant stress and erratic watering due to my work and travel schedule, but the other week they started blooming with big, showy blue flowers. With a wide array of varieties on the market, hydrangeas can add visual interest and beauty to any landscape in our area.
The hortensia genus consists of over 70 different native Asian and American flowering plants. Due to the wide number of species and varieties available, there is a hydrangea to fit any growing situation. Many Asian varieties are evergreen, but all of the hydrangeas we recommend in Georgia are deciduous and lose their leaves in the winter. Some varieties prefer full sun, while others like semi-shade or full shade. Some varieties are small, reaching 2-3’ in height, while others can be up to 15’ tall. All hydrangeas are going to have a medium growth rate and produce showy flowers (more on that in a moment). It’s important that you select a hydrangea variety that meets the needs of your landscape – don’t plant a 15’ variety in a front garden bed; or a variety that prefers shade in full sun. Some of the most common varieties recommended in the Southeast include Oakleaf, Annabelle, Panicled, and Bigleaf hydrangeas.
Hydrangeas are a popular landscape plant due to their flowers, which are usually produced from early spring to late autumn. Hydrangeas produce two types of flowers- small fertile ones that aren’t particularly pretty, and large, colorful ones at the end of their stems. Most of our landscape varieties have been bred for the size and number of those large, colorful flowers. Hydrangea flowers, specifically those in the H. macrophylla variety, are often classified into “mophead” and “lacecap” styles, based on the appearance of the flowers. While hydrangea flowers are beautiful on the plant, they do not make good cut flowers as they wilt quickly.
If you’ve read my articles in the past, you know how important soil testing is for determining the pH and nutrients available to the plants you’re trying to grow. One of the most interesting characteristics about hydrangeas is that their flowers change colors in response to soil pH. When hydrangeas are planted in soil with a pH of 5.5 or lower, the flowers will be blue. If the pH is 6.5 or higher, the flowers will be pink. Soil between 5.5 and 6.5 will produce purple flowers. The exception to this are varieties that have been specifically bred to have white flowers, as they do not produce pigment for color. In some varieties, like Hydrangea macrophylla, the availability of aluminum in the soil can also impact flower color.
Hydrangeas can be a fabulous addition to any landscape as a result of their pretty foliage and showy flowers. If you need more information on recommended varieties in Georgia, check out UGA Bulletin 625: Landscape Plants for Georgia, or contact our office at uge3181@uga.edu or 706-359-3233.
