Betula papyrifera, commonly called paper birch or canoe birch, is primarily native to the cold climates of Canada and Alaska (USDA Zones 1-3), with its range dipping down into a few of the northern U.S. states (USDA Zones 4-5A) and further south in the mountains (to Colorado in the Rockies and to North Carolina in the Appalachians). This tree is noted for its white bark, which exfoliates in papery strips to reveal an orange-brown inner bark. Mature trees develop black markings on the white bark. Single trunk trees grow to 50-70’ tall with an oval rounded crown. Multi-trunked trees grow shorter with a more irregular crown. Ovate, irregularly toothed, dark green leaves (to 4” long). Quality clear yellow fall color. Tiny monoecious flowers appear in early spring in separate catkins on the same tree: yellowish-brown male flowers in drooping catkins (to 4” long) and greenish female flowers in smaller, upright catkins (to 1 1/4” long). Female flowers are followed by drooping cone-like fruits containing numerous small winged seeds that typically mature in late summer. The use of the bark for making birch bark canoes is well known. Garden Uses. In cool northern climates, paper birch is an excellent landscape tree that mixes well with evergreens and produces good fall color.
The seeds have a dormancy period. They need a period of chilling which simulates winter conditions to break their dormancy.
- Soak the seeds in water for 24 hours.
- Fully drain away all of the water and place the seeds in a zip-lock freezer bag.
- Put the bag in the refrigerator and leave it there for 4-6 weeks. It is important that during this period the seeds do not dry out or are waterlogged otherwise the pre-treatment will be ineffective.
- The seeds like moist, well-drained soil. Prepare a mixture of half potting soil and half sand, perlite or vermiculite. Put the soil in a pot.
- Sow the seeds on the soil.
- Cover the seeds with a thin layer of soil.
- Water the soil so that it is moist but not wet. The seeds start to germinate in a few weeks.
- When the seedlings are a few inches tall, they can be transplanted.