Hydrangea macrophylla ‘All Summer Beauty’

'All Summer Beauty' answers the oldest complaint about mophead hydrangeas: that a single hard freeze or an eager pruner can wipe out a whole season of bloom. Where classic bigleaf hydrangeas flower only on old wood, this compact selection, three to four feet high and wide, blooms on both old and new growth, so the rounded heads keep coming through the season and return even after a winter that kills the older stems. The name is a promise the plant generally keeps.

Hydrangea macrophylla, the bigleaf or French hydrangea, came to Western gardens from Japan and remains the hydrangea most people picture: glossy, serrated leaves and dense mophead clusters of sterile florets. 'All Summer Beauty' carries the family's famous party trick, flowers that read the soil. In acid ground the blooms turn clear blue, in alkaline ground they shift to pink, and the color can be nudged either way by adding sulfur for blue or garden lime for pink. Few garden plants wear their soil chemistry so openly.

The species has a quiet ceremonial life in Japan, where a closely allied sweet-leaved hydrangea furnishes amacha, a sweet tea brewed from fermented leaves and poured over statues of the Buddha each spring to mark his birthday. The ornamental mopheads are not that tea plant, and hydrangea leaves in general contain cyanide-releasing compounds and should not be eaten, but the association gives the genus a gentle place in the culture of its homeland beyond mere decoration.

In the garden, 'All Summer Beauty' suits the smaller border, the foundation planting, and the large container, and the bigleaf clan's noted tolerance of salt air makes the shrub a fixture of seaside gardens. Give the plant morning sun and afternoon shade in hot regions, steady moisture, and shelter from drying wind. Deadheading spent globes encourages a fresh flush, and a mass of the blue or pink heads reads beautifully against a dark wall, a hedge, or the green of a shaded bed.