What should you do with old uniforms?

I apologize if this has been covered before...But what do you do with old uniforms? My son left his enlisted ASU's behind when he commissioned. He says they don't fit and he doesn't want them shipped to him. In this day and age of stolen valor, I hesitate donating it. Our municipal trash pickup does not want fabric in the landfill trash.
I have many sets of ACU's as well. Those are well worn and not in any condition to donate...
Any creative suggestions?