Climbing Hydrangea

Climbing hydrangea is one of a short list of ornamental vines that will actually grow in dry shade in the Puget Sound lowlands, and probably the best-flowering option on that list. It clings to walls, trunks, and fences with aerial rootlets (no trellis required once established) and produces flat white lacecap flower heads in June. The two field realities to manage here are slow establishment and final scale. Plants routinely sit and sulk for two to four years after transplant, making very little visible top growth while they build a root system; gardeners frequently conclude the plant is failing and replace it during this phase. Given time, the same plant can reach 30-50 ft on a tall tree trunk or tall wall, so scale matters at site selection. Once established (year 4 or 5 onward), climbing hydrangea tolerates the dry-shade conditions under mature conifers better than almost any other flowering vine, and it is long-lived on the order of decades. The most common local failure mode is impatience: replanting twice during the three-year sulk window and blaming the species. Plant it once, mulch it, water it through the first two summers, and wait.

— Chris Welch, ISA Certified Arborist