Spiraea
Spiraea japonica
A compact, easy-going deciduous shrub producing flat clusters of tiny pink, red or white flowers in summer. Many cultivars offer colourful foliage in shades of gold, lime green or bronze-red, providing interest from spring through autumn. Hardy throughout the UK and tolerant of most soils. Excellent for small gardens, low borders, mixed plantings and informal hedging.
How to grow spiraea
Plant in autumn or spring in any reasonable garden soil. Spiraea flowers most freely in full sun but tolerates light shade. Water regularly during the first season. Once established, it needs very little care. Mulch in spring with garden compost. Feed with a balanced fertiliser after pruning. Golden-leaved cultivars such as 'Goldflame' and 'Gold Mound' produce the brightest foliage colour in full sun. For ground cover on banks or difficult slopes, plant 45cm apart. Spiraea also grows well in containers on patios. Autumn leaf colour on many cultivars is an attractive bronze-orange, extending the season of interest well into October.
Pruning
Prune hard in early spring, cutting all stems back to about 15-20cm from the ground. This encourages strong, colourful new foliage and large flower heads on the current season's growth. Deadhead after the first flush to encourage a second, lighter flowering. Without annual pruning, plants become woody and less floriferous.
Propagation
- Softwood cuttings in early summer
- Semi-ripe cuttings in midsummer
- Division of established clumps in autumn
Common problems
- Aphids on young growth
- Occasional powdery mildew
- Reversion to green foliage on variegated cultivars