I'm presuming you are talking about cutting off lower branches to get a better view of the culms. You can do this anytime...it's not like pruning a tree, because you don't have growth or re-growth at a cut branch. At most, it might make the upper branches a little leafier, but it won't cause stress unless you remove a large quantity of branches/leaves (like more than 1/3 to 1/2). The only caution I would give is to leave any new culms alone until the fall because you want to let them get to full height before messing with them.

Thnks and yes lower branches is correct.
Canes you only remove older ones as well?

If, for some reason you wanted to cut out a whole culm, you could. But I generally don't do this until it's old and not putting out much in the way of foliage. You can probably expect a culm to last about 6-7 years before it starts to lose color, turn a flat-looking tan, and die. The only reason I remove a younger culm is when it's growing where I don't want it to, or if I want to make a division for transplanting or repotting, and then I dig out enough rhizome to support it.