I had one on slight slope in clay soil next to a pond here reach several yards in height in few to several years. As many in this genus are high mountain plants growing with other cooler climate kinds such as spruces and rhododendrons in the wild, it might actually be less vigorous there. I don't know.

bboy, could you be more specific about the height?

No, I have not measured it. You can't plan with plants that precisely anyway, you could get quite a different response from different stock on a different site in a different climate. Height expectations given by other sources are always only representative.

Unlike other shrubs bamboos do have a maximum potential height that is not exceeded, on those occasions when it is reached.