Wait for early spring to divide the clumps. This allows you to plant the young bamboo cutting before new growth begins.
Look for less mature growth and a healthy looking cutting that is attached to the older section of the plant. The part where it attaches to the more mature plant is swollen looking and hard. This is called the rhizome. Look for a perfect cutting on the perimeter of the old plant.
Cut the clump you want to propagate with a sharp ax or saw blade. Cut a section of the plant that is about 1 foot in height and 2 feet wide. Choose a clump with three or four stems on it. The rhizome should have a bright -- not dark -- color.
Dig up the young bamboo so that a clump of soil is attached to the plant. This helps it thrive in the new location.
Maintain moisture on the soil ball. The new cutting won't survive without constant moisture at the roots. Wrap plastic around the ball -- after watering it -- if you are not going to plant it right away.
Plant the bamboo division in an area with moist, well-drained soil. It prefers full sun but many species tolerate partial shade. Cover the roots with about 4 inches of soil. They prefer fertile loam, but do not tolerate soggy soil.