Species

Spiraea japonicaJapanese Spirea

15 other cultivars

shrub RHS Award

Shirobana Japanese Spirea

Spiraea japonica 'Shirobana'

The Story

Plant Bio

Spiraea japonica is a dense, mounding deciduous shrub valued for its long bloom period and ease of care. It typically features flat-topped clusters (corymbs) of small flowers in summer.

'Shirobana' (also sold as 'Genpei') is unique because it produces separate clusters of both deep pink and pure white flowers simultaneously on the same plant. This creates a striking and unusual two-toned effect throughout its blooming season.

Uses & Benefits:

The primary appeal of 'Shirobana' is its whimsical and unique floral display, with both pink and white flowers appearing on the same plant. This novelty makes it a delightful conversation piece in the garden. Its neat, mounding habit and attractive foliage provide a solid structure in borders and foundation plantings.

This spirea is exceptionally easy to grow, adaptable to a wide range of soils, and requires minimal maintenance beyond an annual pruning. Its compact size makes it suitable for small gardens, containers, and lining walkways. It is also reliably deer and rabbit resistant.

The flat-topped flower clusters are attractive to a variety of pollinators, including butterflies and bees, providing a valuable nectar source in early to mid-summer. It serves as a useful 'filler' plant in a pollinator-focused garden design.

SpeciesSpiraea japonicaJapanese Spirea

Essentials

At a Glance

Plant Type

Shrub

Height

30"

Width

36"

Light

Full Sun, Partial Sun

Zones

4, 5, 6, 7, 8

Water

Moderate

Humidity

Adaptable

Lifespan

15-20 years

Native To

Japan, China, Korea

Toxicity

Non-toxic

Bloom period

Early summer – Mid-summer

In flower about 2 months of the year

Planting

How to Grow

Plant in spring or fall in a location with full sun for best flowering.
It adapts to most well-drained soils; amend with compost for best results.
Dig a hole that is twice as wide as the plant's container.
Place the plant in the hole, with the top of the root ball level with the soil.
Backfill with soil, press firmly, and water well.
Keep the soil consistently moist during the first growing season.

Pro Tip

To maintain the pink and white flower mix, prune out any branches that consistently produce only one color.

Keep It Thriving

Care Guide

Do

Provide at least 6 hours of sun for optimal blooming.
Deadhead spent flowers to encourage reblooming and keep the plant tidy.
Prune in late winter or early spring, as it blooms on new wood.
Water regularly, especially in hot, dry weather.

Don't

Do not plant in poorly drained, waterlogged soil.
Avoid planting in deep shade, which will result in poor flowering.
Don't let the plant dry out completely for extended periods.
Avoid heavy pruning in late summer or fall.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Deadhead
Fertilize
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Unique low border or edging plantEye-catching accent in mixed perennial bedsColorful mass planting for summer interest

Companion Plants

Hemerocallis 'Stella de Oro'Nepeta 'Walker's Low'Geranium 'Rozanne'Heuchera 'Caramel'Sedum 'Autumn Joy'

Multiply

Propagation Methods

Good to Know

Common Questions

Shirobana Japanese Spirea questions

What zones can Shirobana Japanese Spirea grow in?

Shirobana Japanese Spirea is hardy in USDA Zones 4–8. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Shirobana Japanese Spirea deer resistant?

Yes — Shirobana Japanese Spirea is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Shirobana Japanese Spirea bloom?

Shirobana Japanese Spirea typically blooms in early summer through mid-summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Shirobana Japanese Spirea need full sun?

Shirobana Japanese Spirea does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.