River birch (Betula nigra)
Mature height: 50 to 75'
Mature width: 35 to 50'
Growth rate: Fast
Plant form: Columnar in youth, rounded at maturity
Deciduous or evergreen: Deciduous
Native range: New Hampshire south to Florida and west to Minnesota and Texas
Native to Minnesota: Yes
Invasive in Minnesota: No
Soil texture: Sandy to clay soils
Soil pH: 4.0 to 6.5
Soil moisture: Prefers moist to wet and well-drained to poorly-drained soils, tolerates some dryness
Hardiness zone: 4 to 9
Pests and stresses: Visit What's wrong with my plant? – Birch for a list of the most common birch pests and stresses in Minnesota.
Other: Tolerant of heat, compacted and poorly drained soils; susceptible to iron chlorosis on high pH soils, resistant to bronze birch borer
The native habitat of river birch in Minnesota is restricted to the Mississippi River floodplain in the southeastern corner of the state. But as a landscape plant, river birch is planted extensively in the southern half of Minnesota. It transplants and establishes easily, grows quickly, and is very adaptable to a wide range of soil textures, moisture levels, and drainage patterns. River birch is restricted only by soil pH levels above 6.5 where foliage chlorosis (yellowing) develops due to iron starvation. Without modification of soil pH or the addition of iron, chlorotic trees will eventually die. When grown on slightly acidic soils, river birch is a beautiful shade tree or accent plant that is grown as a single-stem specimen or as a multi-stemmed tree with three or more trunks. B. nigra is also resistant to the bronze birch borer that is a destructive pest on many other birch species.
River birch has multiple seasons of interest. As a young and middle-aged tree, river birch is a slender columnar tree with beautiful ivory, tan, and cinnamon peeling bark that adds interest year round. 2-4" male flowers called catkins add winter interest as they dangle from stems. Pollen from male flowers fertilize small 1/2 - 1 1/2" erect female catkins produced in spring. When they are pollinated, they develop into catkins full of winged seed that are dispersed by wind, water, or gravity. 2-4" triangular, toothed, dark green leaves provide shade in summer before turning bright yellow in autumn.
Cultivars have been selected for improved bark color, larger or variegated foliage, and compact or weeping plant habit.
Some cultivars grown in Minnesota:
|Cultivar||Foliage color||Growth habit||Size
(h x w)
|Heritage®||Glossy green||Oval||50' x 35'|
|Fox Valley®||Glossy green||Compact broad oval||10' x 12'|
|'Summer Cascade'||Green||Weeping||8' x 12'|
|'Shiloh Splash'||Variegated white and green||Pyramidal, upright oval||30' x 15'|