Want to remove a summer's worth of dirt from your outdoor furniture?  It's easy with these tips.  For plastic furnishings mix a little dish soap, some borax, and half a cup of peroxide into one gallon of water.  Let the mixture sit for 10 to 15 minutes and use it to scrub all your plastic outdoor furniture with a nylon brush before rinsing well.  Just test a small area first to be sure the peroxide does not react negatively with the furniture. 

For wood furniture, oil the wood surfaces with a sealant or preservative that is appropriate to the material.  You can clean the furniture a couple of times a month with an oil soap.  For metal furniture, use soapy water and elbow grease.  Remove any rust or stains with sand paper.  You can also plan to repaint the entire piece next season with a rust prohibiting paint or a metal varnish.  And don't forget to cover up your furniture to protect it during the off-season.