Protecting a Hammock Swing from the Weather

I love our hammock swing which we have on our screened in porch. I want it to last a long time. I have a cover to help protect it from rain and night humidity. I made the cover by cutting the bottom off a commercial size trash bag and cut the side to open it up. It gave me a 71 inch by 58 inch piece of plastic.

To prepare the hammock to be covered, I place the pillows on top of the bar and lay the chair part of the hammock over the pillows. After placing the plastic over this, I lap the sides and secure them with clothespins so they will not be open