Shrubs

Oakleaf Hydrangea: Queen of the Shade

Oakleaf hydrangea

Regal is an adjective we might use to describe a majestic oak or other large trees, but it’s not usually the first word that comes to mind when viewing flowering shrubs. Nevertheless, I felt the need to curtsey, if not bow down, when I first saw a magnificent grouping of oakleaf hydrangea (Hydrangea quercifolia) at my father-in-law’s house in west Alabama. The shrubs’ bright white flowers gleamed in a shady corner of his woodland garden.

Oakleaf Hydrangea History

Although oakleaf hydrangeas were new to me on that occasion almost 30 years ago, they have been making their way into gardens since before 1800. The shrub was discovered and named by the colonial plant explorer William Bartram, who found it growing on a riverbank in central Georgia. Oakleaf hydrangea’s natural range is from Georgia south to Florida and west to Louisiana, but the shrub is most plentiful in Mississippi and in Alabama where it is designated the state’s official wildflower. Oakleaf was immediately popular after Bartram wrote about it in 1791, describing it as “singular and beautiful.”

Oakleaf hydrangea

Oakleaf hydrangea as it changes color / John Thomas

Although these hale from farther south, oakleaf hydrangeas are perfectly at home in our area of North Carolina. Very few plants offer as much for shady gardens. Large white flowers that peak in June are just the beginning of the show. As summer progresses, the flowers age from white to shades of pink to deep rose. The plant’s sturdy leaves resemble those of oak trees and provide beautiful fall color—often a deep burgundy on plants that receive a bit of morning sun. After the leaves have fallen, the shrub’s structure and exfoliating bark lend texture and interest all winter.

How to Grow Oakleaf Hydrangea

Oakleaf hydrangea is truly a majestic shrub. The species typically reach feet tall and wide in size, while some selections including H. quercifolia ‘Alice’ can reach 12 feet tall and wide in the right setting. Their large size makes oakleaf hydrangeas ideal understory plants in woodland gardens with spaces to fill; however, in smaller gardens, their ranginess can make
them too much of a good thing.

Fortunately, gardeners and nurserymen have identified a number of selections compact enough to fit in almost any garden. ‘Pee Wee’ is a selection discovered in the Alabama Sandhills that matures at about 4 feet tall and wide. Two recent introductions from the U.S. National Arboretum, ‘Ruby Slippers’ and ‘Munchkin’, are also compact in size, but feature larger, showier flowers than ‘Pee Wee.’ ‘Munchkin’ holds its flowers upright and ‘Ruby Slippers’ is noted for the speed with which the flowers go from white to pink to rose.

Size is not the only attribute that has led to named selections of oakleaf hydrangea. ‘Amethyst’ was chosen by Georgia plantsman Michael Dirr for the flowers’ quick transition from white to pink. While typical oakleaf growth habit is a bit sprawling, ‘Snow Queen’ has an upright form and holds its flowers erect.

In contrast, ‘Snowflake,’ discovered near Hoover, Alabama, has 15-inch long flowers that can bend the shrub’s branches to the ground. These enormous blooms with multiple bracts that look like double flowers are irresistible to gardeners who enjoy arranging flowers.

Oakleaf hydrangea

Oakleaf hydrangea / John Thomas

When sited correctly, oakleaf hydrangeas require very little attention. They are drought-tolerant once established, but often need supplemental watering the first two years, especially in sunnier spots. In the Triangle area, they thrive in the morning or filtered sunlight with shade in the afternoon. Oakleaf hydrangeas also perform well in all but the deepest shade.

While not fussy about soil types— sand or clay is okay—oakleaf hydrangeas do require good drainage. I learned this lesson the hard way after killing two of them in a wet spot. Subsequently, I planted H. quercifolia ‘Alice’ on a slope in high canopy shade where it has been happy for almost 20 years.

Pruning oakleaf should be limited to removing deadwood and minimal shaping. If pruning is necessary, it should be done by July because the shrubs bloom on old wood. Blooms remain attractive into winter but may be deadheaded in late winter or early spring. Oakleaf isn’t a deer favorite like H. macrophylla, though spraying with a repellant may be necessary depending on your amount of deer grazing.

Many people, including myself, consider oakleaf hydrangea to be the most beautiful shrub native to North America. Thanks to the many selections that have been introduced, there’s a spot for this regal beauty in almost any garden.

Featured image: Oakleaf hydrangea ‘Alica’ / Dale Batchelor

Dale Batchelor owns Gardener by Nature LLC, a residential design and consultation company in Raleigh emphasizing sustainable landscapes and native plants. With her husband, John Thomas, she co-created Swiftbrook Gardens, a habitat certified by the N.C. Native Plant Society and the National Wildlife Federation.