Question
Hello!  My orchid bloomed and was doing really well, then when all of the flowers finished blooming and wilted, I cut back the stem and re-potted it in what I believe is wood chips and coal bits with styrofoam packing peanuts in the bottom.  Now it has started growing another little blossom branch and a new leaf, yet I'm troubled because the old leaves seem to be getting wrinkly and flimsy and the top of the stem where I cut it back it has turned brown, crisp and dry.  I'm worried.  The soil doesn't retain water very well, and I live in a dry dorm, so I covered it with clear bags and put a cup of water with it so hopefully it will stay humid, but I really don't know what's going on or if I'm slowly killing it.  Please help me!

Answer
Kelsey, I will assume that you have a phalaenopsis orchid.  First, Phalaenopsis flower spikes may either stay green after flowering or may turn brown and die back.  It has nothing to so with the way you treated the plant (ie it will not help to cut the green flower spike if its destiny is to turn brown and die back).  This is function of the genetics of the particular type of phalaenopsis hybrid you have.

More importantly, you should have used a standard orchid potting mix found in garden centers.  You also should check the root system before repotting and remove any mushy roots (these are dead or dying).  It sounds like you may have some rotted roots which is why the old leaves are not doing well.  Also, the potting mix that you have used (ie fir bark and charcoal) retains little water when fresh and you should have some white perlite in it (which it should have if it's an orchid potting mix.  I would not use much styrofoam in the pot bottom (maybe one or  two pieces) as this could result in a potting mix that dries out too quickly.  When you get fresh orchid potting mix and it is dry, it is worthwhile to soak it well before use.  Firbark, particularly, is hydrophobic (ie repels water)