Spiraea x billiardii

The Spiraea x billiardii is one of those hardy shrubs that are abundantly planted in old gardens, often surviving complete neglect and forming large impenetrable thickets over the years. From a large and upright bush, numerous long, fluffy, deep pink and shiny spikes emerge in summer, attracting many pollinating insects. Like all spireas, this undemanding plant has its place in an informal, rural or flowery hedge, including in a small garden.

This Spirea, from the rose family, is likely a natural hybrid resulting from the cross-breeding of the Douglas Spirea, native to the western part of North America, and the S. salicifolia, native to southeastern Europe and Asia, up to Japan. These plants grow in cool and damp areas and can be found in nature growing in ditches or undergrowth. However, the billiardii hybrid also performs well in occasionally dry, and poor soils.

The growth of this bush is rapid and its mature size will reach about 2m (6to 7ft) in all directions. Lateral growth occurs through suckers that grow on the periphery of the stump, from which numerous slender, upright, downy, reddish-brown branches emerge. The habit of this spirea is upright, dense, and very bushy. The deciduous foliage is composed of oblong, lanceolate, dentate-edged leaves, 10cm (3.9in) long. They are dark green on the upper side and grey underneath, then turn yellow before falling in autumn. Flowering takes place in July-August in the form of very dense conical panicles that appear at the ends of the branches. They are 10 to 12cm (4.7in) long and composed of numerous small, cup-shaped, intense pink flowers from which stamens emerge, giving the inflorescence its fluffy appearance.

This spirea will be particularly attractive in a flowering or informal hedge, where it will bring diversity. Fast-growing and perfectly tolerant of pruning, it will quickly add elegance to the garden. This very bushy shrub can also adorn the back of a border, alongside mauve hollyhocks or buddleias. In a small garden, it can stand alone in the centre of a small border composed of perennial geraniums, catmints, blue and white campanulas, or lavender in drier soil. It will also thrive near a water feature, mixed with purple loosestrifes and reed maces, for example.