If you would say that there is no need to clean the furniture outside because simply they are just left outside and they are the getting the dreading heat of the sun, oh well you are wrong. Furniture outside also need some pampering and cleaning and to do that oh well here some tips:
Wipe your plastic furniture with wipe cloth damped with mixture of water and liquid detergent soap. Rinse it with hose.
For Wicker Furniture, you can use soft scrub damped with water and a mild oil base soap. You can wash it with hose every few weeks to prevent any build up in crevices.