In the picture is my garden bamboo which I want to trim from both the sides and the top. Can a bamboo be shortened without killing it. Will the leafy tops appear at the new height?
Not as far as I'm aware.
However you can lighten the clump by taking out every other stem, or even 1 in 3 or 4 if you prefer, right down to the base and then, if you like, remove all the leaves on the remaining stems up to your shoulder or head height depending on preference. This will make the clump more transparent and airy.
remove the old stems once the new ones are about 2-3 feet tall in spring, you can also remove the branches/side shoots/leaves up to about half the height of the stems once they've reached their full height.
Thanks for the info, I will thin it out and see what it looks like. My issue is it blocks the light towards the end of the day.