Spiraea nipponica. Photo by Gerard O'Brien.
Snowmound (Spiraea nipponica) puts on a fantastic
flowering display in late spring and early summer.
This delightful deciduous shrub has mid-blue/green foliage
that is produced from new red stems which gracefully arch,
forming an attractive rounded shrub. Masses of small white
flowers sit above the foliage which smother the shrub, making
this plant a real crowd-pleaser at this time of year.
It is fairly fast growing and will reach 1.5m in two to three
years. It's a low-maintenance plant that can be trimmed back
to keep it looking nice and compact and prevent leggy growth.
Older shoots can be removed at ground level to keep the
height down and encourage new growth from the base, keeping
the plant vigorous.
This is usually done straight after flowering, but the plant
can be pruned any time after flowering, from late summer
until it starts to produce new buds in early spring. Hard
pruning at ground level after flowering is recommended if the
plant has become very overgrown.
Propagate by softwood cuttings in summer.
It prefers full sun with a moist free-draining loam but will
tolerate a wide range of soils.
A planting can be seen growing along the edge of the Clive
Lister Garden on the main pathway through the Lower Botanic
- Stephen Bishop is curator of the Clive Lister Garden
at Dunedin Botanic Garden.