Japanese spiraea Spiraea japonica
Japanese spiraea (Spiraea japonica) is a deciduous perennial shrub in the Rosaceae family, native to Japan, with spread to China and Korea. It grows 60 cm–1.5 m (24 in–4.9 ft) tall and 90 cm–1.5 m (35 in–4.9 ft) wide, wants full sun and moderate water, and is hardy to about -34 °C (-29 °F). Space plants about 1 m (3.3 ft) apart.
Plan Japanese spiraea in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Japanese spiraea at a glance
| Type | Perennial shrub, deciduous |
|---|---|
| Family | Rosaceae |
| Mature height | 60 cm–1.5 m (24 in–4.9 ft) |
| Mature spread | 90 cm–1.5 m (35 in–4.9 ft) |
| Spacing | 1 m (3.3 ft) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance low |
| Soil pH | 5.5–7.5 |
| Cold hardiness | About -34 °C (-29 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 33 °C (91 °F) |
| Flowering | from about June for 6–13 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Native to | Japan, with spread to China and Korea |
| Common in gardens of | 🇯🇵 Japan, 🇺🇸 United States, 🇩🇪 Germany |
| Invasive in | US (eastern states, notably the Appalachian region): check local rules before planting |
Is Japanese spiraea toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
No toxicity reported in standard poison references.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Japanese spiraea
Good neighbours
- good With Garlic chives: Gardeners plant garlic chives among roses to deter aphids and black spot; the evidence is weak and mostly anecdotal. Evidence D
Questions about Japanese spiraea
- How far apart should I plant Japanese spiraea?
- About 1 m (3.3 ft) apart, centre to centre. A mature plant spreads 90 cm–1.5 m (35 in–4.9 ft).
- Does Japanese spiraea need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Japanese spiraea need?
- Moderate water. Drought tolerance is low and waterlogging tolerance low.
- How cold-hardy is Japanese spiraea?
- It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.
- When does Japanese spiraea flower?
- From about June for 6–13 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Japanese spiraea poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. No toxicity reported in standard poison references.
- What grows well with Japanese spiraea?
- Gardeners plant garlic chives among roses to deter aphids and black spot; the evidence is weak and mostly anecdotal.
Sources and evidence
Evidence grade C (C: plausible, mixed evidence).
- RHS Plant Finder, Royal Horticultural Society
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- CABI Invasive Species Compendium, CABI
Notes and assumptions
- Typical garden-form values; cultivars and local conditions differ.
- Blooms on new wood, so cut back in late winter; seedlings escape in parts of the eastern US.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Strawberry Fragaria x ananassa
- Dwarf apple tree Malus domestica
- Common ninebark Physocarpus opulifolius
- Serviceberry Amelanchier canadensis
- Raspberry Rubus idaeus
- Blackberry Rubus fruticosus agg.
- Garden rose Rosa x hybrida
- Japanese flowering cherry Prunus serrulata