River Birch
Betula nigra
Betulaceae · broadleaf deciduous tree · native
Last updated
Recommended replacement for B. pendula in Puget Sound landscapes. Immune to bronze birch borer (0% rhododendrin; Santamour 1999). Heritage cultivar widely proven. Tolerates wet soils and clay. Requires acidic soil (pH 3.0-6.5); iron chlorosis possible in amended or alkaline soils. Fox Valley cultivar (dwarf, ~10 ft) available for smaller spaces.
— Chris Welch, ISA Certified Arborist
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
Phenological Calendar
| Stage | Typical Window |
|---|---|
| Bud break BBCH 07 | Feb 15-Mar 15 |
| Leaf emergence BBCH 11 | Mar 1-Apr 1 |
| Bloom start BBCH 61 | Apr 1-Apr 30 |
| Bloom end / petal fall BBCH 69 | Apr 15-May 15 |
| Fruit/seed development BBCH 71 | Mar 15-May 31 |
| Leaf drop BBCH 93 | Oct 15-Nov 30 |
| Dormancy BBCH 97 | Nov 15-Feb 28 |