Not to sure about the mold but I pretty sure that u can still grow there you just have to find a solution. As for the musty smell, maybe ur closet needs to air out. Leave the door opened with ur window up when ur not around. You must do something about the mold. Get some disinfected cleaner:what: sorry I'm not a mold expert I cant help to much there. It might be a good idea to cover ur closet walls with strong plastic covers, they are usually used when painting. Lets see if u get more input as to what esle can be done but u can def grow in that space, so dont worry to much