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rose spirea

Spiraea douglasii · Rosaceae

rose spirea (Spiraea douglasii)
Photo: (c) Gavin Slater, some rights reserved (CC BY) · CC BY · via iNaturalist

rose spirea (Spiraea douglasii) is a perennial shrub in the Rosaceae family. It is native to North America. USDA records it as hardy in zone 4 and warmer, down to about -23°F.

At a glance

Typeshrub USDA
Lifecycleperennial USDA
Native statusnative USDA
Mature height7 ft USDA
Lightfull-sun USDA
Water needlow USDA
Growth ratemoderate USDA
Soil pH5.5–7.5 USDA
BloomJuly USDA
Flower colorPurple USDA
Hardiness zones4 and warmer USDA
Guild layershrub Derived
Nursery availabilityRoutinely Available USDA

USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.

Growing conditions

It needs full sun. USDA rates it as having low water needs once established. Its drought tolerance is rated medium. It tolerates saturated, poorly drained ground well (USDA rates its anaerobic tolerance high). It is recorded on soils from pH 5.5 to 7.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 4.

Size and growth

At maturity it reaches about 7 ft, making it a plant that will finish above head height. It grows at a moderate rate.

Bloom period

USDA records a bloom period of July. Flowers are purple.

A flowering date, not a pollinator rating.

Foliage, flower and season

Summer foliage is dark green, coarse in texture. Its flowers are conspicuous. Its active growth period is spring and summer. USDA rates its lifespan as long.

What the site needs to provide

USDA records it across sites receiving 16 to 50 inches of annual precipitation. It needs at least 100 frost-free days to finish its season. It roots to at least 16 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.

Propagating it

It takes readily from seed, cuttings, bare root and container stock. Seed needs cold stratification — a period of moist chilling — before it will germinate, so sow in autumn or chill it artificially before a spring sowing. Its seed spreads at a slow rate. It spreads vegetatively at a moderate rate.

Resilience and wildlife

Browsing animals rate it barely palatable — the sourced basis for calling it deer-resistant. Its fire tolerance is rated high, and it can resprout after damage. Its growth form is recorded as rhizomatous.

Role in a guild

Shrub layer. In a layered planting this is woody mid-level structure between the understory and the ground. The layer is derived by a fixed rule from growth habit and mature height.

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Tags

deciduousdrought-toleranthedgewet-tolerantsandy-soildeer-resistantspreadingnativefull-sun

Related plants

Others in Spiraea

Similar role and hardiness

Where this data comes from

Every value on this page comes from the USDA PLANTS database record for symbol SPDO, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.

Read our full data sources and methodology.

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