Ammonia

Ammonia is often listed as a primary ingredient in commercial outdoor furniture cleaning products because it’s very effective at killing and preventing bacteria, including mold growth. Mix two parts ammonia to one part water in a spray bottle, then spray onto the affected area and wipe clean with a cloth or sponge. Ammonia can irritate the skin and eyes, so you’ll want to wear gloves and eye protection when applying it. For best results, move your furniture into direct sunlight after rinsing off the ammonia, so the sun can help kill off some of the molds. You can use ammonia on all types of outdoor furniture, but it may discolor stone or metal surfaces.
Borax

Borax is a natural mineral that kills mold and bacteria. Mix borax with hot water until it forms a paste, then spread it over the affected area and allow it to dry. Once completely dry, rinse with warm water and scrub away with a brush or sponge. If leftover mold is present, wipe the area with a mixture of half vinegar and half water, and scrub once more.
Power Washer

A pressure washer often proves to be an effective way of removing mold from surfaces made of plastic, stone, or metal. However, using a power washer on wood may damage the surface by causing it to peel away. If you want to use a power washer on your furniture’s exterior for this purpose, test it out on a small, inconspicuous area first to make sure it will not damage it.
When using a power washer, start by setting your power washer to the lowest pressure setting so that you do not damage the surface of your furniture. Use a solution of warm water with a small amount of dish soap added to it in a bucket or garden sprayer. Turn on your power washer and start spraying down the surface, being careful not to hold the nozzle too close for the risk of damage. Allow all remaining water to drain off before moving your furniture into the sunlight or storing your furniture.
Dish Soap

You can use mild dish soap to remove mold from outdoor furniture without the worry of causing damage. Add a few drops of dish soap and warm water to a spray bottle or bucket, then use it like you would any other cleaning product. However, you should avoid using too much soap, as it could leave behind an unpleasant residue that attracts dirt and dust. If you’re worried about the smell of vinegar or ammonia on your furniture, dish soap can be a great alternative to mask the smell. Dish soap is safe for most outdoor furniture types.
Conclusion
The environment in which we live is full of different contaminants. Things can get out of hand when you don’t know what to do about them, but fear not! An excellent way to make sure your outdoor furniture stays clean and free from mold is to make sure to catch it at the first sign of its growth. Hopefully, with these tips and tricks, you’ll be well on your way to enjoying your outdoor furniture worry-free!