Botanical Names: Hydrangea arborescens ‘Annabelle’, French hydrangea (Hydrangea macrophylla)
Set your sights on a favorite hydrangea that opens flower heads up to a foot across. ‘Annabelle’ hydrangea may be less well-known than the blue and pink French hydrangea (Hydrangea macrophylla), but it’s definitely a hydrangea worth investigating. ‘Annabelle’ is a naturally occurring cultivar that was found in the wild near Anna, Illinois.
Botanically, it’s known as Hydrangea arborescens ‘Annabelle,’ a variety of smooth hydrangea.The straight species of smooth hydrangea is native to Eastern parts of the United States. ‘Annabelle’ is officially hardy to Zone 3, although gardeners in Zone 2 report success wintering it over.
‘Annabelle’ performs like a perennial in the far north, often dying back to soil during winter. This doesn’t affect flowering, because this hydrangea shrub forms its blooms on new wood. In other regions, experts recommend cutting ‘Annabelle’ hydrangea back to 6 inches high in early spring to encourage plentiful blooms on new stems.
When ‘Annabelle’ hydrangea flowers, the blossoms open in symmetrical, rounded heads that measure 8 to 12 inches across. The large flower heads are stunning, but rains can bend top-heavy stems to the ground. To support plants unobtrusively, slip hoop-type stakes into soil early in the growing season so stems are supported as they grow. Some gardeners plant ‘Annabelle’ hydrangea along a fence for an ornamental support.
You can also prune stems less, cutting them back to 18 to 24 inches in spring (instead of 6 inches). This method allows the base of stems to grow stouter and thicker over time, becoming more capable of supporting blossom weight. Pruning stems higher only works in warmer zones where plants don’t die to the ground in winter.
Protect Hydrangeas Over Winter With Mulch
"The mulch’s job is to create a more consistent environment than what is happening outside," says Ryan McEnaney from Bailey Nurseries. "In some parts of the country, temperatures can fluctuate from -10 to 30 degrees in a week or two. As that happens, water molecules in the ground freeze (contract) and then melt (expanding), disrupting the root system (heaving). Mulch helps alleviate those dramatic changes to protect the plants."
In terms of siting ‘Annabelle’ hydrangea in the garden, aim for a spot that receives morning sunlight and afternoon shade. This is especially important in the South and West, where these pretty hydrangea shrubs can even thrive in all day high, dappled shade. In more northern locations, ‘Annabelle’ hydrangea withstands all day sun. Make sure plants receive more sun the further north you live, because too much shade yields fewer blooms.
When buying ‘Annabelle’ hydrangeas, purchase plants in bloom to ensure you get the type offlower head you want. Sometimes the native Hydrangea arborescens is sold alongside ‘Annabelle.’ It flowers are less showy and more fuzzy. You can also find pink Hydrangea arborescens varieties, such as ‘Invincibelle Spirit’ or ‘Bella Anna.’
In the garden, use ‘Annabelle’ hydrangea to provide a backdrop for a perennial border, or as an informal hedge. It also fits nicely into a mixed shrub border or native plant garden design. ‘Annabelle’ hydrangea blends beautifully into woodland settings in the South where sunlight is dappled.