Shalom Atlas wrote:
CUT
there are old stems and decayed parts about two feet high all around the
fresh growth. If I just remove as much of the decayed growth as possible
will I do any damage to the plant?

Removing the dead parts will not harm a thing, though I am sure some of
them will be difficult to get at around the live growth.

Further, unless the plant is in really bad health you can safely remove
quite a few shorter culms (stems) and lower branches if you think it
will make the plant more beautiful. Bamboo is a grass... A very large
grass, but a grass nonetheless. If you don't go way overboard, this
sort of trimming is no more harmful than mowing your lawn.

I am told the Japanese have a saying that goes something like this: "In
a bamboo grove, you should be able to walk with an open umbrella
between the culms." I am sure this applies more to large Madake or Moso
forests when taken literally, but smaller groves can often benefit from
removal of some culms so that you get a good and elegant view of the
others.

Final note: If you chop up whatever you take out, and put it back in as
mulch, the plant will regain important nutrients from it over time.

Cheers!