How Does Your Hydrangea Grow?
We grow hydrangeas for their large, showy flower heads. The dried flowers look great on the plant, in a vase or in a wreath. But this is one of the most common questions asked of master gardeners: “Why doesn’t my hydrangea bloom?”
If this sounds familiar, you’re not alone. The probable answer is that you may have a bigleaf (Hydrangea macrophylla).
This variety, our Midwest problem child, evolved in the mild maritime climate of coastal Japan. Indiana’s crazy spring weather, which jumps between 85 degrees and 20 degrees in one week, is perfect for killing the flower buds.
When we purchase them, no one tells us that they need winter protection for their buds. But once you know, you can defend them from the cold. Tie together the stems, and stuff oak leaves among and around the stems. Then, either wrap them in burlap or put a fence around the plants to help hold up the blossoms. This shields the flower buds so they don’t swell up when it is warm and get destroyed by below-freezing temperatures. Even the new “rebloomers,” such as Endless Summer bigleaf hydrangea that bloom on new and old wood, will disappoint if not protected for the winter.
And if that doesn’t work, don’t be discouraged. Three other great hydrangea shrubs require no cold-weather care.
Panicle (hydrangea paniculata) prefers full sun. The white blooms mature with pink blushes that continue into rosy pink. The stems provide strong support for the enormous pyramidal flowers. Not only is the plant extremely durable, it also gets better with age. Limelight is the most popular new cultivar.
Smooth (hydrangea arborescens) is shade tolerant. June blooms bring flowers starting out light green in color, then transforming into bright white and fading to brown in the fall. Cut back the plant 18 to 24 inches from the ground in late winter. Annabelle, the most popular cultivar, may need to be staked because of heavy blooms.
Oakleaf (hydrangea quercifolia) gets its name from the deep green leaves that resemble oak leaves. Like the smooth hydrangea, the Oakleaf’s cone-shaped flower heads begin as light green in early summer, progressing to bright white before turning brown in the autumn. This sun-loving shrub reaches 4 feet to 6 feet in height and width. It has long-lasting, beautiful fall leaf color.
No matter what variety you have, hydrangeas do not have to be pruned. In fact, other reasons for lack of flowering are improper pruning, as well as too much shade.
And one more tip – all hydrangeas prefer an acidic, well-drained soil.