What makes bamboo such a fun plant to grow is the expectation: how many shoots will you get this year? how fat will they be? where will they come up?
After the shoots emerge and start growing these questions have been answered, leaving just one more: how tall will they get this year?
For very young plants, it's hard to guess. You could get an 8' tall shoot from a plant that was only 1' tall the previous year, or you can get several 4' culms. You could also get no height increase -- there are many factors that determine this, many of them a mystery. For plants that are more established, it may be a little easier to predict the height of the new growth, but there are still surprises.
For a few of my plants I expected a height increase of about 4' (1.2m). This Phyllostachys nigra appears to have done just about that:
This one (Phyllostachys glauca 'Yunzhu') really got taller and thicker this year, much more than the 4' I was expecting:
Others haven't stopped growing yet, so I don't know what their final height gain will be.
The smaller species like Fargesia 'Rufa' get about 18-24" (45-60cm) taller each year at first:
Once they leaf out though the thin culms bend over, diminishing the height increase.
We'll see what happens though, as these look a bit stiffer than they have been in past years.
Recently the repair technician reoriented our satellite dish (which was being blocked by the top of a neighbor's tree) so it points directly over the top of the bamboo that is 6' in front of it. I told him that the bamboo will be growing several feet in the next month and will block reception again. He said that they'd deal with that when it happens. Nice. See you again soon!
So taller is better when it comes to bamboo -- but not always.