In summer, river birch displays attractive medium-green, slightly glossy leaves with sharply toothed margins. The foliage turns a pleasant yellow in the fall. But perhaps the most noticeable of river birch's ornamental features is its shaggy, peeling bark in shades of cream, tan, orange and brown.
River birch is more heat tolerant than many birch species, making it a good landscape choice in much of the country. Another big plus is its resistance to bronze birch borer, the insect pest that has killed many white-barked birches.
Common name: River birch
Botanical name: Betula nigra
Plant type: Deciduous tree
Zones: 4 to 9
Height: 40 to 70 feet
• Sun: Full sun or partial shade
• Soil: Adaptable to most soil types including clay; needs somewhat acidic soil (pH less than 7)
• Moisture: Evenly moist; somewhat drought tolerant once established
• Mulch: 2 to 3 inches organic mulch
• Pruning: Prune in late winter to remove dead or broken branches and improve form.
• Fertilizer: Apply compost or soluble fertilizer as needed.
Pests and diseases
• Leaf miners and aphids are occasional pests.
• Dura-Heat (‘BNMTF') is well adapted to the hot, humid conditions of the Southeast. • Heritage (‘Cully') has handsome cream- to salmon-colored bark and is generally lighter colored than the species.
• ‘Little King' (also sold as Fox Valley) is a dwarf cultivar that develops a neat, mushroom-shaped crown and grows only 10 to 15 feet tall.
• ‘Summer Cascade' has gracefully weeping branches (it must be staked or grafted on a standard to form a small tree).
• As the name suggests, river birch often grows in moist river bottom areas. Its ability to grow in periodically flooded soils makes it a good choice for rain gardens.
• For a lovely winter landscape, plant river birch with evergreen conifers plus shrubs or small trees with colorful, persistent fruit like crabapples, winterberry (Ilex verticillata) and many viburnums.
• River birch often develops iron chlorosis (yellowing of leaves between the leaf veins) in alkaline soils (pH over 7.0). A soil test will tell you the pH of your soil.
All in the family
• River birch is a member of the birch family (Betulaceae), which contains six genera and about 200 species of trees and shrubs.
• Other plant groups within this family include the hazelnuts (Corylus), alders (Alnus) and hornbeams (Carpinus).
• There are over 100 species of birch worldwide, mostly native to cooler regions of North America, Europe and Asia.
Where to buy
• Broken Arrow Nursery, brokenarrownursery.com
• Forestfarm, forestfarm.com
photo by Sue Sweeney