Bamboo grown in beautiful ornamental pots or containers can look quite stunning. The combination of sizes, textures, colours and shapes to go with your bamboo is limitless. Growing in pots gives flexibility in manoeuvring in the garden, patio or balcony. Because the pot itself is a barrier, there is no need to be concerned of bamboo taking over the garden. Because bamboo achieves tall heights in small growing spaces, it is very ideal for those balconies/patios with tight spaces.
Most species of bamboo can be grown in pots or containers. However, care and maintenance can potentially be more involved depending on the species and pot sizes chosen.
As with any plant (not just bamboo), they all eventually outgrow their pots and their roots become 'root bound'. For bamboo, some species grow much more vigoriously than others and therefore will get root bound much quicker. If bamboo remains root bound for too long, it will suffer as there are no more nutrients for the roots to seek out. Leaves do not grow as green or dense. New shoots do not emerge as often and the new culms do not grow as thick or tall. For this reason, bamboo will need to either be re-potted or divided.
Choosing a Bamboo For Your Container
Choosing a bamboo for your container is quite similar to choosing a bamboo for your garden. You will need to know the amount of sunlight or shade your desired location will get. Most importantly, choose a bamboo that is cold hardy enough for your location. Is the bamboo for a privacy screen? If so, how tall or dense? The Bamboo Species section will list the hardiness, light tolerance and growth characteristics.
Running Bamboos will generally give the best height (if that is the objective). Because they are running bamboos, their roots are much more vigorous growing and will get root bound much sooner.
Clumping Bamboos do not grow as aggressively and therefore will generally last much longer in pots before they get root bound and need repotting. Generally, most clumping Bamboos will not achieve the heights that a running bamboo would in a similar sized container.
When a containerized bamboo gets root bound, it will either need to be repotted into a bigger container or it can be divided and replenished with fresh new soil. If dividing, the best time is either in Fall or Winter. Disturbing the root balls during the active growing seasons (Spring and Summer) may potentially destroy the bamboo. Repotting into a larger pot can be done anytime of the year. Care needs to be taken to not disturb the root ball if this is done during the Spring or Summer months.
Dividing and repotting bamboo may sound discouraging to some, but it is a fairly simple task and only needs to be done every 3 - 5 years (depending on species and size of pot). One has to trim trees, branches and mow the lawn on a regualar basis. So if you compare this to repotting bamboo once every few years, it is not much more effort in the bigger picture.
Winter Protection For Potted Bamboo (for extreme cold areas)
Although most potted bamboos will survive a typical winter here in the Pacific Northwest, precautions should be taken during extreme freezes.
As with most potted plants, bamboo in containers are much more susceptible to cold temperatures. Because potted bamboo is not in the ground, it does not get the benefit of a natural water supply in the moist winter soil. It also does not have the insulation effect of the soil surrounding the roots during winter. The root system in a pot is very vulnerable to freezing. In areas of extreme cold, wrapping the pot in insulating material such as burlap or moving it indoors is recommended. A regular watering routine will help make sure the roots receive enough water throughout the winter. Mulching will also help prevent freezing to the root ball. See Mulching Bamboo.
Potted Bamboo During Hot Temperatures
Bamboo grown in containers are also sensitive to hot temperatures and strong winds. Hot temperatures and winds evaporate moisture quicker. Potted bamboo does not have the benefit of moisture deeper in the soil to maintain a water supply during extreme heat. During summertime, potted bamboos need watering every other day and more often during extreme heat periods.
Bamboo Growth In Pots
The size of the root ball is directly related to the size of the bamboo. The bigger the root ball, the bigger the bamboo. The smaller the root ball, the smaller the bamboo. Because the growing area in pots is limited, the growth potential of bamboo is also limited. This translates to much shorter bamboos with thinner canes when grown in pots. Bamboo grown in pots will never reach the sizes of the same species grown in the ground. If tall and thick canes is the objective, then getting the biggest possible pot will give the best potential for size.
Pots For Bamboo
When choosing a pot for bamboo, always choose something that is low profile or squats lower to the ground. Ideally, the pot should be wider than it is deep. Because bamboo is a tall plant, it is easier for wind to tip it over in a taller or light pot. Putting gravel or rocks at the bottom of a pot will make it bottom heavy and will less likely be blown over.