Spiraea cantoniensis

Spiraea cantoniensis with new growth of Miscanthus sinensis Variegatus

Known colloquially as the may bush, this spring-flowering shrub can grow to 2m tall. In September it is smothered in frothy pure white fountains of bloom, each flower like a posy of single or double tiny blooms. It looks at its best when its long branches are allowed to arch over, so sufficient space must be allowed for it to achieve this natural form. A few whole branches can be pruned right back to the base of the shrub each year immediately after flowering to allow this shape to be maintained. It looks particularly fetching when it weeps over a low front fence or retaining wall, or grown as an informal hedge. Some people like to clip it into a ball shape or a formal hedge. Whilst once I felt this treatment destroys its appeal, in recent times I have clipped my specimen into a dome, because it was being swamped by other plants in its border, and its loose shape was a liability rather than a feature.

Spiraea cantoniensis

Like many of the shrubs which appear in our spring gardens, the may bush originates in China. It will flower best in sunny spot in moist, well-drained soil, but it is an adaptable plant and copes well with quite ordinary garden positions. It was traditionally grown with evergreen azaleas in Sydney gardens; I like it as part of a scheme with other pure white flowers of September such Primula malacoides and a big white-flowered Abutilon, along with the pristine emerging foliage of white-striped grass Miscanthus sinensis 'Variegatus'.

Flowers in August, September.