The shoot of the bamboo plant (called a "culm" in horticultural vernacular) provides the plant with its most recognizable visual characteristic and a simple method of propagation. Many mature bamboo plants exhibit a prolific growth that provides ample culm stock for propagation. Following a few general guidelines, an interested gardener can take one bamboo shoot and turn it into two.
Select a culm (stem or shoot) to cut. Choose a shoot according to both its age and its diameter. The shoot should be past one season old, but no older than three. Choose a shoot with a diameter that ranges between 1/2 and 2 inches. Search for these pieces around the perimeter of a plant's cluster.
Use pruning shears to cut the shoot at its base, as close to the ground as possible. Cut straight across the stem, not at an angle. Lay the shoot flat on the ground. Use pruning shears to remove the portion of the shoot with a diameter less than 1/2 inch. Attempt to cut approximately 1 inch above the shoot's node ("nodes" are the raised ribs that intermittently circle a bamboo cane's shaft). Discard the thin piece.
Make propagation cuttings. Cut the bamboo shoot at approximately 4 inches below each node. Use the garden shears to make clean, straight cuts. Continue to create these cuttings until the diameter of the shoot exceeds 2 inches. Remove the smallest branches from the cuttings.
Mix 1 part peat moss with 3 parts garden soil to create a seed-starting mixture. Use a garden spade to scoop the ingredients into a seed flat. Mix the ingredients by hand until combined.
Place the cuttings into the soil-filled seed flat. Place the cuttings flat or at a 20-degree angle. Each cutting's node must be completely covered with the soil mixture. Use your hands to gently pack the soil in place. Water the cuttings well and keep moist for six to eight weeks or until new growth appears.