Western Mountain Ash

Sorbus scopulina

Hosts 1 caterpillarBird foodPollinator plant

Growing it

When	Flowers June to July; fruits August to October
Type	shrub
Sun	Full sun, partial shade
Water	Low, medium
Soil	pH 5.5–7
Hardiness	zone 3–7
Mature height	4 m
Mature spread	3.75 m
Spacing	2.5 m
Years to maturity	5
Bloom	Jun–Jul
Flower colour	White not verified, a genus-level estimate
In bloom	June July
Fruit	Aug–Oct
Native to	AB

feather-compound leaves about 18 cm long; several stems from the base

Where it has been recorded

BothSpecimensObservations

29 squares of about 28 km, each holding at least one record. A square is not a claim that the plant grows throughout it, and an unshaded square is unrecorded rather than empty. Darker squares hold more records, which follows roads and towns as much as it follows the plant. 21 herbarium specimens and 20 field observations this project may redraw. A filled dot is a pressed sheet somebody can re-examine; a hollow ring is a photograph identified by community agreement. Where the dots are dense is where people have looked, not where the plant is commonest, and empty ground is unsurveyed rather than unoccupied. How this map is made.

Which ecoregions the records fall in

Northern Continental Divide south AB: 14 records, medium confidence
Western Alberta Upland central AB: 8 records, medium confidence
Athabasca Plain north AB / SK: 4 records, low confidence
Cypress Upland south AB / SK: 4 records, low confidence
Eastern Continental Ranges central AB: 4 records, low confidence
Fescue Grassland south AB: 3 records, low confidence
Mid-Boreal Uplands central AB / SK: 3 records, low confidence

These are counts of records collected somewhere in the region, which is the resolution of the evidence: the map above shows where inside it. A region with 3 records is not the same claim as one with three hundred, so the count travels with the region. A region missing from this list means nobody has recorded it there, which is not the same as the plant being absent. Records within 900 m of a border count for neither side, because the border is not drawn finely enough to say which one they are on. Source: GBIF occurrence search + PRESERVED_SPECIMEN pass, retrieved 2026-08-24. Boundaries digitised from the National Ecological Framework for Canada v2.2 (Ecological Stratification Working Group 1995), simplified to about 900 m for display: an outline is accurate to roughly a kilometre, not to the metre. How these counts are made.

See every observation, live and current, on GBIF or iNaturalist.

Documented animals

5 documented relationships.

nectar for

Black-tailed Bumble Bee Specimen records from www.bumblebeewatch.org
Brown-tailed Bumble Bee Specimen records from www.bumblebeewatch.org

fruit for

American Robin Cornell Lab of Ornithology
Cedar Waxwing Cornell Lab of Ornithology

caterpillar host for

Canadian Tiger Swallowtail Pohl et al. 2018

Also worth knowing

Safety

Toxicity not assessed, absence of a warning is not a guarantee of safety

Edible parts

Fruit

Buying it

About $25–$50 per plant (estimate), usually from a native-plant nursery. Estimate (shrub default); AB retail as of 2026

Where these numbers came from

Flower detail: not verified, a genus-level estimate