I have had all my birdhouse gourds hanging to dry outside and moved them in to hang in the workshop Friday. Today(3 days later) I went out there and noticed half of them have white fuzzy stuff on them, I am guessing it's mold or mildew.

I know that they get black and icky looking while they dry, but I have never heard of this. Is it normal? I washed one off and it came off easily, but then I went on and scrubbed the skin off too- it was ready. Several of them that have the white fuzz on them are still green though, and I dont want to mess them up!