Betula occidentalis (Water Birch)


Michael's Opinion

It can be found along riverbanks, streamsides and edges in the wild. A relative of the popular Paper Birch, Water Birch has shiny, reddish bark. Its multiple stems and glossy leaves grow quickly to provide an attractive specimen tree or a screen for a pond or creek. Green catkins appear in the spring, and brown conelike catkins that hold the mature seeds ripen in the autumn.

Botanical Information

FamilyBetulaceae
GenusBetula
Speciesoccidentalis
CategoryWoody
TypeShrub (deciduous)
OriginNative to western North America, in Canada from the Yukon east to western Ontario and southwards.
Pronunciation

Details

USDA Hardiness Zone4 - 6
USDA Hardiness Ref.
Canadian Hardiness Zone2a - 6a
Canada Hardiness Ref.
RHS Hardiness ZoneH7 - H6
RHS Hardiness Ref.
Temperature (°C)(-32) - (-18)C
Temperature (°F)(-25) - 0
Height6-10 m
Spread6-9 m
GrowthMedium
Flowering PeriodApril

Description and Growing Information

General DescriptionIt is a deciduous shrub or small tree growing to 10 m high, usually with multiple trunks. The bark is dark red-brown to blackish, and smooth but not exfoliating. This species has been placed on the IUCN Red List as least concern.
ID CharacteristicKnown for its shrubby form often with several spreading trunks.
ShapeThe water birch is a small coarse shrub with several spreading trunks.
PropagationIt has a slow ability to spread through seed production and the seedlings have medium vigor.
PestsNo serious pests.
Bark/Stem DescriptionThin and smooth, but dotted with conspicuous lenticles, almost black when young, but turning reddish-brown to copper-coloured as it ages. Older bark may loosen and curl, but does not exfoliate.
Flower/Leaf Bud DescriptionBuds are small, red-brown, and very resinous.
Leaf DescriptionThe leaves are alternate, oval to rhombic, 1–7 cm long and 1-4.5 cm broad, with a serrated margin and two to six pairs of veins.
Flower DescriptionSmall (about 2.5 cm long), cylindrical, cone-like structures (catkins or aments). Between the scales of this "cone" grow the seeds that are tiny nutlets. As the "cone" ripens, the entire structure disintegrates, and the seeds are dropped.
Fruit DescriptionTiny, hairy nutlets with wings broader than the seed. Thousands of seeds are produced from each tree.
Colour DescriptionFlower colour yellow. The leaves are shiny and dotted with fine glands underneath.
Texture DescriptionThe bark is smooth, red brown, twigs have a warty texture due to numerous resin glands.

Photographs