In some cases patio furniture cushions can be washed in the washing machine. Before doing so always be sure to check the label to make sure that it is safe to wash the material. The cushions are tagged with instructions for cleaning. Depending on the fabric, and more importantly, the filling, you may or may not be able to launder them. Zip-off covers can usually be washed but not put in the dryer. Again, read the label for specifics.