Before you can actually thoroughly clean your patio, we will need some clearing operation. It means taking away items that can cause damage and items that can be ruined during winter.
Remove items that cover your deck or patio flooring. Usually we use floor mats, carpets or rugs to cover our floor and as additional outdoor decoration. These will catch and hold moisture. The materials can be a good ground for mold and other organisms that aid in their deterioration and the materials where it is on.
Things like some patio furniture items especially those made of wood or real wicker patio furniture sets are vulnerable to rot. You can store them inside your house or garage. They can be left outdoors but be sure they are properly sealed and provided with cover.
The same goes to patio umbrellas. You can store them away but make it sure they are properly cleaned and dried to avoid mold and rust. Some umbrellas such as fiberglass and aluminum patio umbrellas can be left outside. Just provide them a protective umbrella cover and securely tie them down.
Here is a useful article on how to clean your patio and on how to remove mold. In addition, here is how you can clean a wooden deck.
A dishwasher soap would suffice in regular deck cleaning. A mixture of about ¼ cup of the soap and a bucket of water is enough. Wet your deck, brush or scrub the mixture, then rinse.
For hard stain, a good pressure washer is best for the job.
Refinishing and Sealing
Sealing your deck or patio adds a protective coating to prevent finish and surface deterioration. In preparation for winter, you should choose a waterproofing wood sealer.
You should remove old or unwanted finish and apply a new one before you seal your deck or patio. You would not want an old and dull looking but newly sealed deck right?
There are many products on removing wood stain or finish and deck sealers. Ask your nearest home improvement and hardware stores for the right type and combination.