grumpy-
I think you may have a misunderstanding about how bamboo grows. When a shoot comes up and turns into a culm, it will typically reach its final height within a matter of weeks; it will also be at its final diameter. Bamboo culms are not like trees where the trunk gets taller and fatter each year. However, if a bamboo has decent growth conditions (light, soil, and water), it will put up new and bigger culms each year until it hits the maximum height for that species. Lastly, bamboo often don't show much significant growth until they're been in the ground 2-3 years. So, some time in the near future -- maybe next year -- you'll start to see your bamboo take off. Until then you'll just have to be patient and not...grumpy.

Thanks