River birch is a handsome, often multi-stemmed, fast growing tree that is native to the central and southeastern United States. Its most notable ornamental feature is its beautiful peeling bark that appears in mixed shades on white, rust-orange, gray and brown. Like other birches, it has elongated catkins, which appear in spring, and its medium-green leaves turn a dirty yellow in the fall. Its seeds ripen in late spring, much earlier than other birch species.
This tree is a wise selection for wet soil sites, hence its name, but can tolerate locations with drier soils. This species is more tolerant of heat than other birches and is resistant to birch borers. One problem with river birch is its tendency to drop many fine branches on the ground, especially after storms. In residential yards, the smaller maturing cultivars make better landscaping options. (info source: Learn2Grow.com)
Genus - Betula
Species - Nigra
Common name - River Birch
Pre-Treatment - Required
Hardiness zones - 5 - 8
Height - 40'-70' / 12.2m - 21.3m
Spread - 40'-60' / 12.2m - 18.3m
Plant type - Medium tree
Vegetation type - Deciduous
Exposure - Full Sun, Partial Shade
Growth rate - Fast
Soil PH - Acidic, Neutral
Soil type - Clay, Loam, Sand, Well Drained
Water requirements - Wet Site
Landscape uses - Feature Plant, Shade Trees
Germination rate - 89%
Bloom season - Spring
Leaf / Flower color - Green, Light Green / Yellow, brown
|Germination||Seeds have an internal dormancy that can be overcome by a moist, chilling period. This treatment is called stratification. Here are the steps to stratify the seeds:|
1. Soak the seeds in water overnight
2. Place the seeds in a moist material such as milled sphagnum peat, sterile soil or vermiculite . Fully drain away all of the water and place the seeds in a zip-lock bag.
3. Refrigerate the seeds for 2-3 months at 33 to 41 degrees Fahrenheit (+2 – +4C).
4. After the seeds are stratified, surface sow in a container filled with a moist, well-drained germination medium. Cover with glass or plastic and keep the container moist, but not soggy. Keep in room temperature.
5. Requires light for germination
As soon as the seeds germinate, place them under bright lights or move them to a greenhouse or cold frame.
You can sow seeds outdoors in well prepared beds in October or before the winter. Nature will do the job and will germinate in spring.
When large enough to handle, prick the seedlings out into individual pots and grow them on in a cold frame for their first winter.