Betula albosinensis – White Chinese Birch (= B. albosinensis septentrionalis)
(north-west China, Tibet, central Asia)
Habit: Small tree, 6-10 m tall, 4-6 m wide; often with picturesque, crooked stem, loosely broad, conical, overall somewhat asymmetrical; slow-growing, 20-25 cm a year.
Flowers: Inconspicuous, monoecious, in yellow catkins, April.
Leaves: Ovoid or elliptical, slightly pointed, light green when shooting, pale green to bluish green in summer; yellow to yellow-orange in autumn starting in September.
Stem: Smooth bark with exceptional colours, from whitish pink to copper-orange, shiny.
Roots: Shallow, sensitive to compaction and pavements.
Demands: Sunny, warm to cool, frost hardy; sensitive to late frost in extreme areas.
Soil: Dry to fresh; slightly acidic to slightly alkaline, in all well drained substrates, not growing much or at all on heavy soil.
Native habitat: The copper birch plays a dominant role in the northern Chinese forests: in mixed conifer forests, on shady, cool northern slopes or even at altitudes 3000 m+ above sea-level. In such areas, it reaches exceptional sizes – 20-30 m a hight it never reaches in Europe. Their partners include numerous species of Abies and Pinus, often also varieties of Acer, Hydrangea, Spiraea, Syringa and various Viburnum. Others are Potentilla fruticosa, Sorbus koehneana and numerous evergreens such as Berberis, Cotoneaster, Rhododendron and, above all, small types of bamboo. Numerous perennials – Aquilegia, Aconitum, Bergenia, Carex, Corydalis, Primula and Tiarella – occur as underplanting.
Hardiness: Zone 6a