Black bamboo enthralls many gardeners with its blackish-brown canes and airy, light-green foliage. When planted en masse, it adds a dramatic element to large gardens and yards with its towering 10-foot-tall canes and lush growth habit. Black bamboo will grow from seed if it is sown when fresh and kept under warm, moist greenhouse conditions. However, the seeds sometimes take up to six months to germinate; thus, do not be discouraged if the seedlings fail to emerge immediately.
Pour seed-starting compost into a bucket or large bowl. Drizzle a small amount of water onto the compost while stirring it by hand. Keep adding water and stirring the seed-starting compost until it feels moderately moist throughout.
Fill 3-inch square pots with the moistened seed-starting compost. Press the compost into the pot to remove any trapped air.
Place two black bamboo seeds on the surface of the seed-starting compost. Cover the seeds with a 1/16-inch-thick layer of compost.
Spritz each pot with a water-filled spray bottle to settle the seed-starting compost around the black bamboo seeds. Spray the compost until the top 1/4-inch feels saturated.
Place a propagation mat near a large window with very bright, filtered light. Set the temperature to 68 degrees Fahrenheit. Set the pots atop the propagation mat.
Moisten the seed-starting compost with the spray bottle whenever it feels dry on the surface. Spray it until the top 1/4-inch becomes saturated. Do not let the seed-starting compost dry out.
Watch for sprouting two weeks after sowing the black bamboo seeds. Be patient, since many black bamboo seeds take up to six months to sprout.
Remove one of the black bamboo seedlings from each pot, if both germinate. Keep the healthier, more vigorous of the two.
Move the black bamboo seedlings to a greenhouse environment with very bright light, high humidity and temperatures above 68 degrees Fahrenheit. Keep the seedlings well-watered and out of direct sunlight.
Transplant the black bamboo plants in a partially shaded bed with loamy, well-draining soil once they grow to 6 inches in height.