Can I grow bamboo in my climate?
Well…maybe? That depends upon your climate and what your expectations are. Among the many factors that ultimately determine how successfully you can grow bamboo, cold winter temperatures are a primary one. Cold air and/or strong winds will desiccate the foliage and depending upon duration/extremes the entire colony of above-ground growth may be killed. This would be bad. The leaves of a bamboo are its primary tool for fueling growth through photosynthesis. To a lessor extent (varying in different species) the culms also contribute to the process. Deprive a bamboo of its leaves*** and it will go into emergency survival mode, spending stored energy for survival rather than for grove expansion. Save for a few rare exceptions of deciduous species, bamboo wants to be an evergreen plant. Growing in its natural environment a healthy planting of bamboo will produce larger diameter & taller culms each shooting season until mature sizes are obtained. The larger the number & size of the culms, the more energy can be generated for expansion of the colony. This upsizing process is a result of the above ground plant parts working in combination with subterranean plant parts (contributing moisture & nutrient absorption to the process) in converting starches/sugars into stored energy for future growth. Damage from cold exposure interrupts the natural growth cycle, hence exposure to cold temperatures has a direct relationship to the size of the culms in a bamboo grove.
If you live in an area that typically experiences winter temperatures below -15C/5F but rarely below -18C/0F there are several species of bamboo that you can grow to mature sizes. If in a normal winter (do those really exist?) you can expect temperatures or wind chills below -18C/0F then you should not expect your bamboo to achieve mature sizes. You still may be able to grow bamboo but you must lower your expectations – you’ll not be able to raise material for a tiki bar or bamboo flooring. And if your ‘normal’ winter contains multiple events of temps much below -20C/-4F then you should start thinking of your bamboo as an ornamental grass which it actually is anyway, albeit a major kickass cool ornamental grass. It will be killed each winter, turn brown/drop leaves in spring and need to be cut down or it will look quite unkempt. Unless the rhizomes are killed by a very deep ground freeze, new shoots will emerge the following spring generally around the beginning of April depending upon species and your location. The new growth though will be much smaller than the now dead culms and you now have a grove of shorter, smaller diameter, leafier bamboo.
There are so many uses for, and things to know about bamboo that I do not endeavor to host a know-all-about-bamboo website. Rather I proffer my observations and opinions relative to my own limited experience with the plant. I can not overstate the fact that the very particular local conditions in which I grow bamboo may be unique and in areas with similarly rated climate zones results may materially differ due to soil types, temperature extremes, humidity, precipitation, and a multitude of other factors. I see cold hardiness ratings on other websites that contradict my own experience and giving benefit of doubt I assume that these are valid statements based on other peoples experience. There are some species of bamboo – in particular the non-spreading montane species of the Fargesia genus – that just do not do well for me in Indiana for some reason. Their cold tolerance in other areas vastly exceeds my own and based on my experience I can not recommend Fargesia though they are beautiful, desirable species that you should by all means try in your area.
The information that I offer will list species that I’ve observed as experiencing minimal leaf damage at the listed air temperatures. Strong winds at these air temps will cause greater damage so in flat, open areas commonly experiencing strong winds you can expect more damage at ‘warmer’ temps. There are photos of each bamboo on the associated links.
My ratings suggest a fairly narrow range of climates suitable for growing cold-sensitive bamboo but I am providing conservative estimates in the hope that you will be pleasantly surprised as opposed to disappointed at the end of winter. Each of the classifications below are intended to offer species that should reach mature sizes in those climate zones. One should be fine growing the species 1 to 1.5 zones below the rating, but you can not expect your bamboo to achieve mature sizes, you should expect frequent winter damage, and you should expect occasional die back of all above ground growth after severe winters.
In climate zone 4 you should expect annual die-back of even the hardiest species ultimately topping out in the 8-10 foot range. Above climate zone 9b you should mostly ignore the running forms of bamboo as they will not do well without experiencing some winter frosts, also topping out far below mature sizes. But do not fret, you can grow the sub/tropical clumping forms so you still have hundreds of species to choose from without concern about your bamboo taking over the entire state of Connecticut.
***Knowing this is key in eliminating the running forms, that by removing the plants’ capacity for photosynthesis you are shutting down the primary energy production system. The grove must expend stored up energy in the rhizomes to try and get more sun absorbing plant parts above ground. A cycle of clear-cutting a grove, letting it expend stored energy to push new above ground growth, clear cutting again – repeat cycle WILL result in the death of a grove as it will eventually exhaust energy reserves and die off, regardless of what a rabid dingbat in Connecticut has posted on the web and told city governments.