River Birch

Betula nigra

Betulaceae · broadleaf deciduous tree · introduced

Last updated May 11, 2026

River birch (Betula nigra, Betulaceae) is a fast-growing deciduous tree native to the eastern United States, from Massachusetts to Florida and west to Missouri and Kansas. It reaches 40 to 70 feet tall with an upright, often multi-stemmed form. The signature feature is exfoliating bark that peels into papery plates, exposing inner bark ranging from gray-brown to cinnamon or reddish-brown, with considerable color variation between individuals. Rhombic-ovate leaves (4 to 9 centimeters) are doubly serrate with lustrous medium to dark green upper surfaces. Fall color is yellow but brief.

River birch thrives in full sun on moist to wet, acidic soils (pH 3.0 to 6.5), hardy in Zones 4a to 8b. It tolerates periodic flooding, clay soils, and urban conditions, with moderate tolerance of anaerobic soils and a minimum root depth of 20 inches. It is a short-lived pioneer species with high water needs. Documented diseases include rust, canker, and wood decay; pest associations include bronze birch borer, birch leafminer, aphids, and oystershell scale. The cultivar 'Heritage' (syn. 'Cully') is widely planted for its tan to creamy-white bark and reported resistance to bronze birch borer. 'Fox Valley' offers a dwarf form at 10 feet. River birch is a larval host for Mourning Cloak, Dreamy Duskywing, and Eastern Tiger Swallowtail butterflies.

Quick Facts

Height

40–70 ft

Spread

40-60 ft

Growth Rate

Fast

Light

Full Sun

Soil

Wet Tolerant

Water

High

Hardiness

Zone Zones 4a–8b

Bloom Time

April to May

Fall Color

Yellow (brief; drops early)

Origin

Eastern United States

RustHigh

Aecial Stage (Alternate Host)

Wood DecayHigh

Wound Infection Window

Birch leafminerHigh

Adult Emergence

Oystershell scaleHigh

Crawler Emergence

+ 4 more — see full disease and pest lists below

Phenological Calendar

Stage	Typical Window	What to Look For
Bud break BBCH 07	Feb 15-Mar 15	Small pointed buds swelling; overwintering male catkin clusters (reddish-green, near branch tips) beginning to elongate
Leaf emergence BBCH 11	Mar 1-Apr 1	First rhombic-ovate leaves unfurling; lustrous medium green above, paler below; doubly serrate margins
Bloom start BBCH 61	Apr 1-Apr 30	Male catkins elongated (5-8 cm), drooping, turning brownish, releasing yellow pollen; smaller upright female catkins (1-2 cm) visible, light green
Bloom end / petal fall BBCH 69	Apr 15-May 15	Male catkins spent and dropping; female catkins thickening into small green strobiles
Fruit/seed maturity BBCH 85	May 1-Jun 30	Small cone-like strobiles turning brown and disintegrating, releasing tiny winged nutlets. Unique among North American birches: seeds ripen and disperse in late spring/early summer, not fall.
Fall color / leaf drop BBCH 93	Oct 15-Nov 30	Leaves turning yellow briefly then dropping quickly; fall color display is short-lived. Exfoliating bark becomes prominent feature after leaf drop.
Dormancy BBCH 97	Nov 15-Feb 28	Leafless; exfoliating bark is the primary ornamental feature in winter. Male catkin clusters (reddish-green) forming near branch tips for next spring's bloom.

Diseases: Regionally Documented (3)

Multiple genera (Melampsoridium, Thekopsora, Naohidemyces... Rust Symptom category — not a single disease Canker Multiple Basidiomycete fungi cause wood decay in trees Wood Decay

Pests: Regionally Documented (9)

Agrilus anxius Bronze birch borer Fenusa pusilla Birch leafminer Aphidoidea Aphid Lepidosaphes ulmi Oystershell scale Choreutis pariana Apple-and-thorn skeletonizer Prionoxystus robiniae Carpenterworm Hyphantria cunea Fall webworm Symphyta Sawfly Malacosoma spp. Tent caterpillar

Cultivars (3)

'Cully' Heritage®

The most widely planted river birch selection. Tan to creamy white exfoliating bark (lighter than species type). Fast-growing, heat tolerant. Discovered by Earl Cully in a St. Louis suburb, introduced circa 1979.

Hardy to USDA Zone 4. Widely proven in Puget Sound landscapes.

'Little King' Fox Valley™

Dwarf form, about 10 ft (3 m) tall x 12 ft (3.6 m) wide. Dense habit with peeling bark. Good for smaller spaces.

Hardy to USDA Zone 4

'BNMTF' Dura-Heat™

Better heat tolerance than Heritage. Smaller, thicker leaves, closer together on twigs, more persistent in fall. 30-40 ft. From a Florida seed source.

Recommended replacement for B. pendula in Puget Sound landscapes. Highly resistant to bronze birch borer (0% rhododendrin; Santamour 1990, 1999). Heritage ('Cully') is the standard cultivar and performs well here. Tolerates wet soils and clay. Requires acidic soil (pH 3.0-6.5); iron chlorosis possible in amended or alkaline soils. Fox Valley ('Little King') dwarf cultivar (~10 ft) available for smaller spaces.

— Chris Welch, ISA Certified Arborist

Data Maturity

Structured Multiple sources. Expert review underway.