Nippon Spiraea 'Snowmound'

Nippon spirea 'Snowmound' (Spiraea nipponica 'Snowmound') turns into a white snowdrift every spring, and the name is no exaggeration at all. Its arching branches are smothered in rounded clusters up to 4 cm across of pure white flowers, while the small dark blue-green leaves stay fresh into late autumn.

In May and June the bush reads as a white fountain, so it is planted as a specimen on a lawn, in informal hedges and on slopes. At 10-20 years it reaches 1.5-2.5 m in height and width, noticeably larger than the summer-flowering Japanese spireas. It blooms on last year's wood, so prune right after flowering, never in spring.

Key characteristics:

• What makes it special: In flower the shrub becomes a magnet for butterflies, drawn to the solid white cloud of blossom that covers every branch.
• Dimensions: Over 10-20 years it grows to 1.5-2.5 m tall and just as wide - a rounded, well-filled shrub.
• Hardiness: Overwinters without cover - it takes frosts down to -40 °C (USDA zone 3).
• Flowering: In May-June the branches are covered with pure white flowers in rounded clusters up to 4 cm.
• Light: Full sun or partial shade; in a hot climate the shrub appreciates light afternoon shading.
• Soil: Takes readily to any garden soil - chalk, loam or sand - as long as it is moist and well-drained; pH does not matter.
• Watering: Moderate, even watering without drying out; the one thing it dislikes is water standing at the roots.
• Care: Prune right after flowering: the flower buds are set on last year's shoots.
• Landscape use: Lovely in cottage and informal gardens, on slopes and banks, in flower borders and free-growing hedges.
• Origin: The cultivar holds the RHS Award of Garden Merit (2002).