It depends upon the fabric of the petticoat. You can wash almost all of them in a gentle wash cycle. However, if it contains an elastic, put it around the agitator and let the petticoat float all over the surface for better and easier cleaning. This is the case with cotton and similar materials. If your costume is lacy or net, then hand washing them would be a better option. So, the wash and care depend upon what kind and what materials of petticoats you have.