Rose Spirea

Spiraea douglasii

Native to:
Canada, United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Rosaceae
Genus:
Spiraea
Species:
Spiraea douglasii
USDA Symbol:
SPDO

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Shrub
Height:
250 cm
Light Requirements:
Part Shade
Drought Tolerance:
Low
Bloom Months:
jun,jul,aug
Bloom Colors:
pink, rose
Landscaping Shrub:
Yes

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)
Butterflies & Moths:
★☆☆☆☆ Documented Lepidoptera association (GBIF)
Caterpillars:
★★☆☆☆ Recorded caterpillar host plant (HOSTS Database)

Keystone Species Ranking

Caterpillar Keystone:
★★★★☆ Butterfly & moth species supported by this genus (NWF)

Host Plant for Caterpillars

Adelphagrotis indeterminata, Elegant Sheep Moth (Hemileuca eglanterina), Orthosia praeses, Orthosia revicta, Spiramater lutra, Spotted Tussock Moth (Lophocampa maculata), Lorquin's admiral (Basilarchia lorquini)

Reported Fauna Sightings

Bees: Brown-belted bumble bee (Bombus griseocollis), Fuzzy-horned bumble bee (Bombus mixtus), Obscure bumble bee (Bombus caliginosus), Red-belted bumble bee (Bombus rufocinctus), Sitka bumble bee (Bombus sitkensis), Two-form bumble bee (Bombus bifarius), Western bumble bee (Bombus occidentalis), Yellow bumble bee (Bombus fervidus), Yellow head bumble bee (Bombus flavifrons), Yellow-faced bumble bee (Bombus vosnesenskii)

Garden & Ecology Notes

Wildlife Value:
birds, butterflies, bees
Fall Color:
yellow, orange
Fire Ecology:
Fire adapted — tolerates or benefits from fire
Fire Notes:
Can resprout from root crown after fire; adapted to periodic disturbance in riparian zones.

Soil Requirements

Soil Type:
moist, rich, well-drained loamy soil
pH:
5.5 - 7.0 (slightly acidic to neutral)
Drainage:
tolerates poor drainage
Moisture:
consistently moist
Notes:
Commonly found in wetlands and riparian areas

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
30–90 days
Notes:
Seeds benefit from cold moist stratification for 30-60 days to break dormancy.

Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).

Source: Claude AI

ORGHPS Germination Guide: Sow @ 10C.

Source: Ontario Rock Garden & Hardy Plant Society

Where to Buy

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