Betula pendula Roth
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Betula pendula is a tree with vary variable growth form that is native to almost the whole of Europe from Siberia to Asia Minor.
Betula pendula was described by Albrecht Wilhelm Roth in 1788. The name is considered as validly published.
The trees are comparatively fast-growing and short-lived; their maximum age is stated at 150 years. They reach heights of 22 to 25 (30) metres and have a slender stem that usually continues rigth to the top. The open canopy is often narrowly conical with a width of 7 to 12 metres. The branches are widespread with finer branches often long and drooping. The main growing season is in spring and summer.
Wood and Bark
Betula pendula is a sapwood-tree, old specimens sometimes form heartwood. The wood is white to reddish yellow, it is medium-dense and soft but at the same time tough and flexible.
The bark of young shoots is grey to dark brown covered with glands. With age the bark turn white and peels off in circles. The bark of the stems is deeply furrowed, silver-grey, fissured, and black at the base.
Betula pendula is deciduous and produces new shoots early in the growing season. The dark-green, simple leaves are alternate. They are rhomboid, denticulate and petiolate. The foliage is porous and turns an attractive light yellow in autumn.
Flowers and Fruits
Betula pendula produces showy spikes (catkins) of pendant, yellow-green cruciform flowers from March to April. The plants are dioecious, pollination takes places by allogamy through the wind.
Birches may produces seeds already at the age of 5. The seeds are brown samaras that are about 3 millimetres long, each catkin produces approx. 450 seeds. They ripen from July to September and are spread by the wind. Provided with enough humidity they will germinate directly, otherwise in the following spring.
The plants have a heart-shaped root system with shallow and spreading primary roots and many fine roots in the uppermost soil layer.
"If the plants do not find sufficient water at a depth of 30 centimetres at the latest they will continue searching and dry up anything around them in the process; Birches are bad neighbours."
The shallow roots often lift pavings and tiled areas; rooted areas in lawns will often show drought damages.
Betula pendula is native to Europe and West-Siberia. It occurs mostly in light forests, on poor soils, marshes and moorlands, usually on acid soils.
It is the most important pioneer tree in Central Europe and usually is the first to populate fallow land, debris fields and clearings.
The trees prefer a sunny situation on dry to moist soil. They prefer sandy, gritty-sandy, sandy-loamy, gritty-loamy, sandy clay, loamy clay or peaty soil with a pH between 5 and 7,5. The plants need a soil depth of at least 61 centimetres for good growth. They tolerate temperatures down to -45Â°C (USDA zone 2) and need a frost-free period of at least 13 weeks. The plants are suited for the soil stabilisation of the shores areas of natural standing bodies of water.
Classification after Prof. Dr. Sieber
- open areas
Tolerance of special soil conditions
- none: anaerobic soil
- low: soil salinity, drought, calcareous soil
- high: city climate, road salt
The ornamental value of Betula pendula lies especially in the attractive autumn aspect. Limited suitable for moorland gardens and for rooftop gardens, furthermore suited as cemetery plant, avenue tree, container plant, specimen plant, greenery along roads, a small canopy tree along roads, bee pasture and as plant providing shelter for birds.
The plants have moderate potential for fuelwood production.
Maintenance and Propagation
The plants can be considered rather high-maintenance: the seeds germinate freely and anywhere where they find enough light and moisture (Preferably also in gutters and the cracks of capstones).
Planting should take place only in spring, pruning should only take place during dormancy from October to January. Pruning into older wood is not well tolerated; cropping the canopy may lead to stem rot and total loss.
B. pendula has no coppice potential at all and can not be propagated vegetatively. The species is propagation by sowing, cultivars by grafting.
Pests and Diseases
Spots on leaves and withering shoots indicate an infection with anthracnose. This is a fungus that may cause the plants to die. Destroy affected parts and improve ventilation and hygiene.
Honeydew, galls and distorted leaves are a sign for an infestation with aphids. Use an insecticide or control biologically , e.g. with parasitic wasps or predators such as Aphidoletes aphidimyza.
Root and stem lesions, often in combination with raised rings of bark and pustules nearby, indicate a fungal infection. Generously cut out and destroy affected parts.
Mealy excreta on leaves, flowers or fruits indicate in infestation with caterpillars. Crush eggs, handpick and destroy caterpillars. Also apply insecticide or use biological pest control.
Leaf blotches are a sign of a fungal or bacterial infection. Bacterial spots are rather angular and yellow-rimmed while fungal spots usually are rather rounded with an area of fruiting bodies. Destroy affected parts, additionaly apply fungizide it is is a fungal infection.
Discoloured and tunneled leaves indicate an infestation with leaf miners. Remove and destroy affected leaves.
Brown, orange or yellowish pustules on shoots and on the leaves lower surfaces are very likely caused by a fungal infestation (rust). Remove affected parts and apply fungicide. Also improve ventilation and reduce humidity.
Disfigured and discoloured leaves and flowers indicate a viral infection. Remove affected plants and control insects that may spread the disease.
- Various visitors of Betula pendula:
- Walter Erhardt, Erich GÃ¶tz, Nils BÃ¶deker, Siegmund Seybold: Der groÃe Zander. Eugen Ulmer KG, Stuttgart 2008, ISBN 978-3-8001-5406-7. (Ger.)
- Christoper Brickell (Editor-in-chief): RHS A-Z Encyclopedia of Garden Plants. Third edition. Dorling Kindersley, London 2003, ISBN 0-7513-3738-2.