Planting Birch Tree Seeds

Birch trees belong to the genus Betula, which includes more than 30 species of deciduous trees found throughout the Northern Hemisphere. Species such as river birch (B. nigra) and monarch birch (B. maximowicziana) grow well within U.S. Department of Agriculture plant hardiness zones 4 to 10, where they are widely planted as landscape ornamentals for their textured bark and heart-shaped leaves. All birch species grow reliably well from fresh seeds. However, they must be stratified before planting and sown under suitably moist, bright conditions to ensure successful germination.


Gather birch seeds in mid- to late summer when the small, 1/2-inch-long cones are still soft and green. Gather several cones in a paper bag. Secure the top of the bag and leave it in a warm, dry area under light shade.


Let the cones dry out for approximately two weeks, or until they begin to dry out and fall apart. Shake the bag vigorously to knock loose the papery, winged seeds. Pick out the seeds and discard the chaff.


Sow the seeds in individual 5-inch greenhouse pots filled with a mix of equal parts coarse sand, milled peat and potting soil. Press the seeds onto the surface and cover them with a 1/16-inch-thick layer of coarse sand. Mist the sand liberally after sowing.


Cover each pot with a plastic bag to hold moisture around the birch seeds. Set the pots inside the refrigerator for two months to cold stratify. Keep the sand mixture evenly moist at all times.


Move the pots to a warm, sunny area such as inside a cold frame or indoors near a large window. Warm the pots with a propagation mat set to between 70 and 85 F during the day and 65 F at night. Keep the sand mixture moist in the top inch at all times.


Watch for germination in four to six weeks. Remove the propagation mat and plastic bag once the birch seeds sprout. Continue to water them regularly. Move the pots to a sheltered, lightly shaded area outdoors once they grow to 1 inch in height.


Grow the birch seedlings under light shade for two to three months, then acclimate them to direct sun. Transplant them into a permanent bed with consistently moist soil and full sun exposure in autumn.