There are many types of bamboo plants and several different methods for pruning them.
Pruning is not usually required until the bamboo has become established. This is generally after your 3rd to 5th growing season.
When a bamboo grove starts to mature, an annual pruning will help to maintain overall health, vigor and attractiveness of the grove. Bamboo culms, what some call canes, typically live for about 10 years. Essentially, pruning is done to remove these dead or damaged culms, which stimulates and frees up space for new growth.
The way you prune can depend on how you intend to use bamboo in the landscape. If you are using bamboo for a hedge or privacy screen, you might not want to cut any culms. Keep in mind that if there is foliage on a culm it is viable and producing energy for the grove. The more energy a bamboo grove has the greater the potential for production of new shoots. That said, if you want to create a trail or walkway through a grove you can remove culms to do so.
When To Prune Bamboo
Bamboo can be pruned any time of the year. That said, to avoid stepping on or damaging new shoots emerging from the ground, I advise waiting to prune or remove dead culms until after the annual spring shooting season, at which time the new shoots have grown taller and are therefore more visible.
Bamboo Pruning Tools
Dead Bamboo culms can be cut to the ground with a pruning saw or most types of handsaws. Bypass hand pruners or lopping pruners can be used to cut smaller branches. When pruning bamboo, make sure to wear safety goggles and thick gloves.
Bamboo Pruning Methods
Before pruning, it's a good idea to first identify and use marker paint to mark damaged or dead culms you want to remove. When removing a dead culm make sure to cut it as close to ground level as possible. This keeps the floor of the grove looking tidy and prevents you or others from tripping and falling over above-ground stumps. Also keep in mind that while you can remove all dead culms with no foliage, removal of more than one-third of good culms can effect the overall health of the grove and it's ability to produce larger culms.
Bamboo Plant Parts
Maintenance Pruning For Large Running Bamboo
Most bamboo can be pruned for shaping or size control purposes without fear of damaging the plant. Just trim so it looks attractive. You can prune any time of year that new shoots are not emerging from the ground. I usually prune my bamboo in late winter, when I'm pruning many other shrubs and trees in the landscape.
When maintenance pruning, older, dead or unattractive culms can be sawed off to ground level. Dead branches can be cut off at their origin. If you will be removing only part of a culm or branch, make cuts just above a node. This way you won't leave a stub that will die back and look unsightly. If you cut back the top, you may want to also shorten some of the side branches so the plant will look more balanced, not leaving long branches at the top. Just remember to make your cuts just above a node.
How To Thin Clumping Bamboo
Clumping bamboo can be pruned to maintain upright growth, or thinned to maintain an airy appearance. If the plant gets too wide, just use a sharp pair of bypass hand pruners to cut some of the outer culms back to ground level. Start by cutting the most weepy culms at the outer base of the plant. Some of the taller culms that weep outward a little too far can be topped by cutting them just above a node about 2 to 3 feet down from the top. This causes them to stand more upright.
Pruning Bamboo For Hedges & Screens
As one might do with boxwood or other hedge plants, bamboo can also be pruned to form a hedge. Do only one major pruning per year. Most of the new growth on a bamboo plant happens at the same time of the year, usually late spring or early summer for temperate bamboos. Therefore, it's best to prune a bamboo hedge after the new canes grow to full height in the spring or summer.
Pruning Bamboo To Control Height
This method of pruning can be safely done with a bamboo that is well established, not a newly planted bamboo. If you want to control the size or height of your bamboo, while still retaining the natural look, this can be done by removing new shoots that are significantly larger in diameter than the culms that are the desired height. These shoots will form smaller diameter culms that will not grow so tall.
Pruning Bamboo For Topiary
To achieve unique topiary shapes and forms, you can top culms, remove some lower branches, shorten some side branches and remove others. Keep in mind that any cut culms or branches will not grow back longer but will only grow more leaves. Also be sure to make your cuts just above a culm or branch node.
Legging Up Bamboo
For display of colorful bamboos that have colorful culms you can enhance the beauty by removing smaller culms and cutting off lower branches so that the beauty of the canes is visible. Cut lower branches off at their origin on the culm.
Pruning Dwarf Bamboo Plants
To maintain nice appearance, it's best to use hedge trimmers or a mower to cut dwarf bamboo plants back to ground level every year, as you would with many ornamental grasses. This helps to rejuvenate the plant and keep it looking dense and bushy. Dwarf bamboos can also be trimmed later in the season to keep them shorter and more uniform in height.