Bamboo grows very quickly, so your plants will need to be repotted when they outgrow their original container. Plants that are root bound (roots are too large for the pot, and are pressed tightly against the walls of the container) will absorb water very slowly and the bamboo will stop growing. If your plant exhibits these symptoms, it's time to repot. The larger your pot, the less often you will need to replant your bamboo, so choose a large container if you want to avoid the hassle.
Choose a container that is at least 2 inches larger on all sides than the bamboo's current pot, or 2 inches larger than the plant's root ball if you are potting bamboo for the first time. Containers with rounded edges that curve outwards at the top will facilitate easier repotting in the future. Your pot does not need to be very deep; bamboo roots will spread out to the sides before they spread down. Find a pot with holes in the bottom for excess water drainage.
Remove the bamboo from its current container and place the root ball in a bucket of water. Allow the roots to soak for several hours to fully hydrate the bamboo.
Mix slow-release fertilizer into your potting soil and cover the bottom of your pot with about 2 inches of the mixture. Slow-release fertilizer will stay in the soil for an extended period of time, which will help supplement regular fertilization. Choose a light, loamy potting soil that will drain well.
Use a handsaw to remove the bottom 10 percent of your bamboo's root ball. Removing the bottom roots will encourage growth. You can also remove the outer roots from the sides of the root ball if desired.
Place the bamboo in its new container, and fill the pot with your potting soil/fertilizer mix to cover the roots. Place the pot on a tray to catch any water drainage.