Betula lenta (Sweet Birch)


Michael's Opinion

This plant is extremly rare in Ontario and is considered critically endangered with only a few trees occuring in one known, isolated location in the province. A great tree to plant on its own and doesn’t need a large space as it grows to be about 12 m in diameter (crown) over a course of 50 years.

Botanical Information

FamilyBetulaceae
GenusBetula
Specieslenta
CategoryWoody
TypeTree (deciduous)
OriginMaine to Alabama, West to Ohio and north into southern Ontario. Introduced into cultivation in 1759.
Ethnobotanical Uses
Disclaimer
Native Americans used medicinally to treat colds, fevers, diarrhea, pains and dysentery.
Pronunciation

Details

USDA Hardiness Zone3
USDA Hardiness Ref.
Canadian Hardiness Zone1a
Canada Hardiness Ref.
RHS Hardiness ZoneH7
RHS Hardiness Ref.
Temperature (°C)-40
Temperature (°F)-40
Height13-20 m
Spread11-13 m
GrowthMedium
Flowering PeriodMay

Description and Growing Information

General DescriptionA seldom grown birch because its bark is too dark to suit the taste of most people and the tree suffers in urbanized settings. Equally tall as broad, with small leaves and a red tint to a brown bark. It has been placed on the IUCN Red List as least concern.
ID CharacteristicLustrous dark green leaves and dark gray bark which breaks into large, thin, irregular scaly plates. Red tint in the brown bark means it’s a cherry birch.
ShapeBroadly pyramidal with a rounded crown when mature.
LandscapeMakes an excellent tree for naturalized areas and parks.
PropagationBirch seeds have low viability, but produce numerous nutlets; 1-2 million seeds per kg. Never plant the seed too deeply, as it needs to be moist, and germination occurs by exposure to light. Collect the seeds from the tree while the catkins are still green.
CultivationReaches its best development in deep, rich, moist, slightly acid and well-drained soils; however, is often found on rocky, drier sites.
PestsLeaf spots, leaf blisters, leaf rust, aphids, canker, dieback, wood-decay and mildew.
Notable SpecimensWestonbirt, The National Arboretum, Tetbury, Gloucestershire, England.
HabitatVery acidic, damp soil, but can tolerate dry soils. Betula lenta grows up to 23 m (crown diameter) at the foot of the Appalachian Mountains.
Bark/Stem DescriptionStem is slender, light reddish brown, glabrous, shiny and contains a strong wintergeen flavour when chewed or smelled. Becomes almost black at full maturity with horizontal lenticles.
Flower/Leaf Bud DescriptionImbricate, conical, sharp-pointed, reddish brown, divergent and terminal.
Leaf DescriptionLeaves are ovate-oblong and are 6-16 cm long. Leaves contain 10-13 vein pairs and are glossy dark green and glabrous above, paler beneath and hairy on the veins.
Flower DescriptionMonoecious, 5-10 cm long, formed during summer and autumn the year before flowering. New buds are formed on new growth but don’t flower until the following year. The pistillate flowers are enclosed in the bud and are borne upright, while the male ca
Fruit DescriptionSmall winged nutlet, 2-4.5 cm long.
Colour DescriptionLeaves are a lustrous dark green in summer which change to a golden yellow in autumn. Bark is glistening reddish brown to almost black on young trees and on mature trees it grows into a brownish black colour.
Texture DescriptionMedium texture.

Photographs