Bamboo growth habit
Bamboo grows more rapidly than any other plant on the planet, It has been clocked surging skyward as fast as 47.6 inches in a 24-hour period.
One of the most asked questions we get when showing our groves:
"How many years did it take for this pole to get this big?"
Our answer: 90 days! However, our answer needs explanation. The culms (poles) of temperate bamboos will usually grow to their full size, both diameter and height, in 90 days or less. At this point we will get a puzzled look and the following question:
"You mean if I plant a single bamboo I will get a pole this tall in 90 days next year?"
By now we are sure you are probably as confused as our visitor.
If you visit any bamboo grove, you will usually find bamboo culms of varying sizes. Regardless of the size, whether it is 1 foot or 60 feet tall, it grew to that size in 90 days or so and will never get any larger. You can put a steel band around a bamboo culm and it will not girdle the culm as it never increases in diameter.
Now to explain why it will not get 60 feet tall next year.
The simple answer is leaf and root mass.
There is a saying about newly planted bamboo:
The first year it sleeps
The second year it creeps
The third year it leaps
For the first 15 years or so everything in your grove is one plant. All the above ground culms are connected by the underground rhizomes. When you plant a single plant, it starts putting out new rhizomes. The root mass will usually double in size each year. As the root mass increases, the energy available for the plant increases and the size of the new culms will increase in diameter and height in direct proportion to this energy.
Where does the energy come from, you ask. This is where leaf mass comes in. The leaves on your new plant transpire water that the roots provide and in return the leaves convert sunlight into food and send it to the rhizomes to use for producing more rhizomes and to store for use for the next year's new shoots. This process will continue until the grove flowers and dies. Critical root mass is when your grove produces the maximum size culms it is going to produce based on local growing conditions. For most varieties this will occur somewhere between 7 and 15 years (up to 30 years for some seedling varieties) and after that the grove will continue to produce the maximum size culms it is able to produce in that particular location.
The sizes of bamboo we sell for UPS shipping (A to D) are basically increases of 2" of diameter and proportional increases in leaf mass for each letter grade. That small increase will basically double the energy the plant has to get off to a good start in your location. The end result of your grove will be the same regardless of the size you start with, the only difference will be the time it takes to get there. The more energy your plant has to start the quicker it will size up.
Even though bamboo is a fast growing plant, don't plant a 6" to 14" root ball and expect a 45-foot culm the next year --- it won't happen. If you plan to plant in containers or small confined areas, start with the size plant you want as the root mass will be restricted and your chances of ever getting a bamboo with a greater height will be small.