Heavenly Hydrangeas

Mark Griffiths extols the beauties of this shrub, from its 18th-century beginnings to its revival in the hands of hydrangea champion Maurice Foster

- Mark Griffiths

IN 1736, Peter Collinson, a London merchant and plant connoisseur, introduced a shrub, seeds of which had been sent to him from its native Virginia. Superficially, it resembled a guelder rose (Viburnum opulus), in that its flowerheads were round, white and composed of a central mass of small, petal-less fertile florets with larger and showy petaloid sterile florets around its periphery.

In 1753, the Swedish botanist Linnaeus named this plant Hydrangea arborescens and made it the first and founding species of his new genus Hydrangea. From the Greek for ‘small water vessel’, the name hydrangea itself was an allusion to the shape of this New World newcomer’s seed capsules and not (as some understandably surmise) to the genus’s habit of fainting in hot weather as if from thirst. Collinson’s shrub became popular with gardeners, as our first and, for a while, only hydrangea.

All that changed in 1789 when Sir Joseph Banks had one of its cousins shipped from China to Kew. This was H. macrophylla, a Japanese native with far more spectacular flowers than H. arborescens, in shades of red, pink, purple and blue. Suddenly, hydrangeas were no longer pure, pale and delicately understated, but bold and brilliantly colourful. This recent introduction was ‘supremely magnificent,’ wrote William Curtis in 1799, if baffling in that ‘it will sometimes happen that a plant which has produced red flowers one year, shall produce blue another, though growing in the same pot’. We did not yet understand that blue-flowered forms of this species and the related H. serrata will turn pink or mauve unless grown in markedly acid soils or treated with aluminium or iron.