Water Birch

Betula occidentalis

Hosts 4 caterpillarsBird food

Growing it

When	Flowers April to May
Type	tree
Sun	Full sun, partial shade
Water	Medium, high
Soil	pH 5.5–7.5
Hardiness	zone 3–7
Mature height	8 m
Mature spread	4.5 m
Spacing	3 m
Years to maturity	12
Bloom	Apr–May
In bloom	April May
Native to	AB, SK

egg-shaped leaves about 4 cm long; several stems from the base

Where it has been recorded

BothSpecimensObservations

99 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. 60 herbarium specimens and 197 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

Fescue Grassland south AB: 428 records, high confidence
Aspen Parkland central AB / SK: 115 records, high confidence
Northern Continental Divide south AB: 58 records, high confidence
Mixed Grassland south AB / SK: 49 records, high confidence
Eastern Continental Ranges central AB: 33 records, high confidence
Moist Mixed Grassland south AB / SK: 22 records, high confidence
Boreal Transition central AB / SK: 9 records, medium confidence
Athabasca Plain north AB / SK: 6 records, low confidence
Mid-Boreal Uplands central AB / SK: 6 records, low confidence
Western Alberta Upland central AB: 5 records, low confidence
Cypress Upland south AB / SK: 4 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

6 documented relationships.

caterpillar host for

Canadian Tiger Swallowtail Acorn & Sheldon 2006
Compton Tortoiseshell Pohl et al. 2018
Mourning Cloak Pohl et al. 2018
Polyphemus Moth Pohl et al. 2018

seed for

Common Redpoll Cornell Lab of Ornithology
Pine Siskin Cornell Lab of Ornithology

Also worth knowing

Safety

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

Edible parts

Sap

Buying it

About $60–$150 per plant (estimate), usually from a native-plant nursery. Estimate (large specimen tree); AB retail as of 2026