It happens. This is best done after flowering or in … Flowering period: June to August; Hardiness: fully hardy A star plant, this climbing Hydrangea thrives in some of the most shady, inhospitable areas of the garden. It grows slowly at the beginning, but … Slow to establish, it will eventually romp along a wall or fence, clinging by aerial roots. But usually when a hydrangea won’t flower, it is a common problem with some simple solutions. This climber is deciduous so it will lose all its leaves in autumn, then fresh new foliage appears again each spring. Bigleaf (H. macrophylla), Oakleaf (H. quercifolia), Mountain (H. serrata), and Climbing hydrangeas (H. anomala subsp. Watering and Feeding . Read on for tips on getting your hydrangea to bloom. A hydrangea not blooming can be frustrating. The bloom period is earlier, beginning in late spring and continuing through midsummer. Horizontal lateral branching often extends several feet beyond supporting structures. Hydrangea anomala, commonly known as climbing hydrangea, is a vigorous, sprawling, deciduous, woody vine that clings and climbs by twining and aerial rootlets along the stems, typically maturing over time to 30-40’ long.