Brush off any leaves or debris on the surface of the furniture.
Apply a thin layer of citrus-based cleaner to a soft cloth and wipe the cleaner all over the pieces. Rinse the cleaner away with your garden hose and then dry the pieces with paper towels.
Wipe down the entire surface of the furniture with a damp paper towels. Rub the wet towels over the top and bottom of all of the furniture pieces to wipe away any ground-in dirt, stains left behind by spilled drinks and any other light stains.
Mix nine parts water with one part bleach in a plastic bucket. Cover your hands with protective rubber gloves and then dip a sponge in the mixture. Wipe down white furniture with the bleach mixture to remove stains and dark spots. Let the pieces dry in the sun.
Combine 1 tbsp. powdered detergent with 1 gallon warm water. Dip a scrub brush into the solution and then transfer the mixture to the resin furniture. Scrub the solution around the furniture, dipping the brush in the solution as needed to remove any debris trapped in the bristles. Rinse the furniture with fresh water.
Cover any chips or imperfections in the piece with alkyd-resin paint. If cleaning the furniture fails to restore it to its original appearance, apply a fresh coat of paint. The paint adheres to the furniture and protects it from the outside elements.