As bamboo grows more canes it can become congested. Smaller, older canes will die back and obscure the fresh vibrant new growth. Periodic cane thinning can help reestablish the health and appeal of a grove. There is no rule to cane thinning, but generally the smaller, old, crowded or dead canes should be removed first. The goal is a clean, balanced look to show off the culms. Winter snow or summer drought can cause the tops to break or die off, and canes should be separated to see which ones need to go. Care should be used not to thin so much that the visual screening is lost, but canes will always grow back anyway.
Annual maintenance is needed to keep a bamboo from spreading out of bounds. Once a pruning trench is established it is patrolled for errant rhizomes at least once during late summer through fall, and is best done 2-3 times during this growing season.