Betula nigra is a large, rapidly growing, Eastern U.S. native. River Birch is a fine-textured shade tree for dry or wet sites and is commonly produced in a multi-trunked form. It has a very attractive peach-colored exfoliating bark and is one of the best and most rapidly growing trees for both shade and ornamental bark.
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F E A T U R E S |
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Form
-large deciduous tree
-maturing at 60' tall x 40' wide
-upright oval growth habit for the species (but often sold in clump form of 3-5 trunks)
-rapid growth rate |
Foliage
-alternate, ovate (broadly triangular), doubly serrated and slightly incised
-medium to dark green upper sides and silvery-colored undersides
-autumn color - yellowish green in poor years, but golden-yellow to yellow-brown in good years |
Flowers
-male catkins to 3" long in Apr.; female flowers inconspicuous |
Fruit
-resemble immature catkins, opening and shedding seeds in spring |
Twig
-red-brown, somewhat shiny, with cinnamon-colored, heavily-lenticeled branches exfoliating (peeling) to a brown-gray-light orange mixture on the species form |
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Trunk
-very scaly to platy
-gray-brown to almost black on the native species form, with selected species forms having peach-purple-colored exfoliating (peeling) bark |
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C U L T
U R E
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Culture
-full sun to partial sun
-prefers moist, slightly acid soils (alkaline soils sometimes result in leaf chlorosis due to iron deficiency) but performs well in either wet or dry soils
-propagated primarily by rooted stem cuttings, but also by seed
-highly resistant to bronze birch borer (a potentially devastating pest of the popular white-barked birches) but susceptible to leaf miners and aphids, especially when under stress
-abundant availability in B&B form
-avoid pruning in spring unless sap bleeding from wounds will be tolerated |
Hardiness
-zones 4 to 9
Origin
-native to Eastern and Midwestern U.S.
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U S A G E |
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Assets
-not subject to bronze birch borer problems as are most birches
-rapid growth rate
-wet or dry site tolerant and heat tolerant
-exfoliating flaky bark
-shimmering bicolor summer foliage
-yellow autumn color in good years
-single trunk or clump forms
-dappled shade
-symmetrical branching
Liabilities
-alkaline soils sometimes yield chlorotic foliage
-a few surface roots with age
-overuse in the urban landscape may be associated with increasing problems such as attack by aphids and leaf miners |
Function
-specimen, focal point, or shade tree (casts a light to medium shade)
Texture
-fine texture in foliage and when bare
-open to average density in foliage but thick density when bare |
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S E L
E C T I 0 N S |
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Varieties
and Cultivars
- Search
OSU PlantFacts for additional plants in this species
Alternates
-trees with distinct ornamental bark, or rapidly growing shade trees |