The first time I saw the cover of the illustrated version of Dirr’s Hardy Trees and Shrubs I was hooked. Spread across the bottom of the book jacket is a big pile of enormous white, mop-head hydrangea blooms, and I wanted that!
Hydrangea arborescens ‘Annabelle’ is such an exuberant plant. Blooming reliably starting in June, the display continues into July when the color begins to fade to lime green. Eventually the heads brown, but selective pruning may produce additional flowering in August.
‘Annabelle’ has a secret to success. It blooms on new wood. Unlike the big leaf (macrophylla) varieties like ‘Nikko Blue’ that bloom on old wood and are often nipped by late cold spells in April or May, smooth leaf (arborescens) varieties send up new shoots in April and May that will produce a great floral display. It prefers filtered light or part sun conditions as with all hydrangeas and fertile soil but tolerates neutral to slightly alkaline soils.
Pruned back to 6-8 inches in late winter, it sends up new shoots in early spring that flower reliably. It spreads readily from the roots, but can also be propagated by stem layering. My original ‘Annabelle’ has provided at least two dozen new plants for my garden. It is easy to dig out the “new” offshoots to create a large display in short order.
The original ‘Annabelle’ thrives in the northwest border of the house. Floppy blooms can be cut for inside display.
‘Annabelle’ works as a groundcover under the crabapple in a northeast border. All 12 of these came from the original shrub.