Whatever the material, "always start with a light cleaning," advises Gardenista
, "sweeping surfaces as needed with a soft brush or cloth. Then assess if more care and cleaning is needed."2) When in doubt, use dish soap mixed with warm water.
This is the cleaning solution that is least likely to cause damage to furniture and upholstery.3) Read the manual!
And if you lost the manual, you can probably find it online. The manufacturer will have instructions on how to properly clean the product.4) Vacuum natural or resin wicker furniture.
Use a soft brush attachment to get deep into those grooves and crevices. If it's still gunky, follow up with a gentle scrub with a soft cloth and/or toothbrush and a water-dish soap mix. Then rinse and let dry overnight—don't sit on wet wicker because it will stretch! Be sure to do this cleaning on a stretch of hot, sunny days to avoid causing mildew.5) Remove rust from metal furniture by sanding with fine-grit sandpaper and touching up with rust-proof paint.
Prevent rust by always cleaning metal with a soft cloth to avoid scratches. Avoid abrasive cleaning solutions. (And if you do see places where the paint or finish has chipped away, be sure to apply touch-up paint.)6) Apply oil to wood furniture (teak, shorea, ipe) after every cleaning.
Aim for every three months. If your furniture is starting to look a little too weathered, use a power washer on "light" mode (or a powerful hose) to blast out embedded dirt. Let it dry, sand, rinse, let dry again, and then finish with oil.7) Remove mildew from outdoor cushions with dish soap, Borax, and water.
Spread out your cushions on a clean, paved surface. Spray with a hose to get them damp, then use a brush to scrub with a solution of 2 tablespoons of dish soap + half a cup of Borax + a gallon of water. Let the solution sit for 5 minutes, then rinse with the hose. Squeeze the excess moisture from the cushions, then lean them vertically against something so they can dry in the sun.