Any part of the leaves including the stem that is still green is providing power to the plant from the sun. I do however from time to time peel some of the old ugly ones off to reveal the nice looking p-stem underneath. I usually do this with my reds because the fresh p-stem looks so cool!

Do this very conservatively as this seems to lessen the bulk to the pstem. When I cut an old leaf off I leave a little of the petiol to dry out on its own. Otherwise it can choke the pstem. Then once they are dried I bend it back and cut it off. From there I only cut stem matter when it has become paper dry and I only cut the papery part. If you are constantly cutting into live matter it is always drying the cut edge so you can loose potential girth at the pstem. This has been my personal experience.

Cut off anything that is brown or yellow. Leave anything that is green (or red, if it is a red banana). Momo1 has it right.

Hi - here's a picture of the plant

{{gwi:413514}}

I'm not sure if you can make it out but the pseudostem is basically covered in dead leaves. Also, can anyone confirm that this is a Dwarf Cavendish? I assume it is, since the tag says "banana dwarf".