There is no more quintessential southern shrub than the hydrangea. It is a beloved old-fashioned plant that graced our grandmothers’ gardens. Back in the day, nothing said “summer” like the large brilliant mophead flowers in pink and blue that bloomed one time but lasted for weeks. Today, with reblooming cultivars available on the market, the flower display is extended for the whole season, making the hydrangea more popular than ever.
There are numerous types of hydrangeas to choose from that can add variety and interest to your garden. Let’s look at a few choices that will thrive in our climate:
Bigleaf Hydrangea (Hydrangea macrophylla): Considered the most popular species of hydrangea, the bigleaf has two bloom types – mophead and lacecap. The mopheads are large globes of flowers in variations of pink, blue or purple. The color is influenced by the pH of the soil. Flowers will be bluer in acidic soil and pinker in alkaline soils. Some favorite reblooming mopheads include ‘Moonlight’ from the Let’s Dance ® series and ‘Blushing Bride’ from the Endless Summer ® series. You can honor Penny McHenry, founder of the American Hydrangea Society, by planting a ‘Penny Mac’ or ‘Mini Penny’ mophead in your garden. And, every fan of the Georgia Bulldogs will want to have a ‘Dooley’ hydrangea, named after legendary Coach Vince Dooley.
The lacecaps are flatter, more subtle flowers with tiny buds in the center and larger showy blooms around the edges. Popular selections include ‘Twist-n-Shout’ from the Endless Summer® series, ‘Beaute Vendomoise,’ (one of the largest lacecaps on the market) and ‘Wedding Gown,’ a reblooming white lacecap.
Bigleaf hydrangeas prefer to be planted where they can get morning sun (3-4 hours) and afternoon shade. Our harsh, late-afternoon summer sun can cause the large leaves to scorch and wilt. Do not assume that the wilting means they need water. Check first to see if they perk up overnight. If they are still wilted, then water them.
Knowing when to prune a bigleaf hydrangea can be tricky. The older varieties set flower buds in the late summer for the coming year. If you prune them from late summer through spring, you will cut off the flower buds for the next year. So, only prune your plants in mid-summer right after blooms have faded to ensure you don’t cut off next year’s buds. The newer reblooming varieties set buds on last year’s growth and on new growth, so even if you prune them in the fall or spring you will still have some flowers. Prune sparingly and only to shape and thin older plants.
Many people want to control the color of their bigleaf hydrangeas. You can experiment using liquid soil drenches. For bluer flowers, dissolve one tablespoon of alum (aluminum sulfate) in one gallon of water and drench the soil around the plant in March and again in April and May. For pinker flowers, add one tablespoon of hydrated lime to one gallon of water and drench soil in March, April and May. Watch that you don’t splash the solution on the leaves.
Oakleaf hydrangea (Hydrangea quercifolia): Every garden should include this wonderful native hydrangea. It tolerates more sun, can take drier conditions and has beautiful oak-shaped leaves that turn a lovely red/burgundy in the fall. The cone-shaped white blooms start in June and last for weeks. Some favorite varieties are ‘Snow Queen’ and ‘Snowflake.’ The oakleaf hydrangea sets new flower buds on last year’s growth, so don’t prune after mid- summer.
Smooth Hydrangea (Hydrangea arboescens): In 1995, ‘Annabelle’ became a Georgia Gold Medal Winner. This summer-blooming shrub features spectacular mophead blossoms that change from green to white to faded brown over the season. It should be placed where you can enjoy it in a shady, moist area of the garden with room to spread. The ‘Annabelle’ can grow 3-5’ high by 4-6’wide. Flowers form on new growth so you can cut back the shrub in March to control the size without cutting off flower buds.
Panicle Hydrangeas (Hydrangea paniculata ) These large shrubs need several hours of sunlight. ‘Limelight’ is a favorite with cone-shaped blooms that start out lime green and turn a creamy white. ‘Chantilly Lace’ has bright white flowers and is smaller than other paniculatas. ‘Bombshell’ is new on the market with prolific white blooms and a compact shape.
The panicle hydrangeas respond very well to pruning and since flowers form on the current year’s stems, you can severely cut back a large shrub in March and will be rewarded with a smaller plant with larger blooms.
Hydrangea Care: Mix organic matter into your beds when planting hydrangeas and make sure they have plenty of room to grow. Limited air circulation and humid weather can cause fungal diseases. Remove any diseased leaves from the beds to curtail the disease next year. In the spring, add some slow-release fertilizer as directed on the label.
For more information about hydrangeas, contact the Fayette County Cooperative Extension and ask for the publication Hydrangeas: A Southern Tradition. To find unusual varieties of hydrangeas locally, visit Wilkerson Mill Gardens near Palmetto.