Mold and mildew has a tendency to grow and thrive wherever moisture is. That being said, outdoor carpet is an ideal place for mold, moss and mildew to attach themselves. It can be more than unsightly. It can be unsanitary as well. Fortunately, mold and mildew are easy to clean up. Doing so will make your outdoor carpet last much longer and look much better.
Vacuum the area free of any mold, moss or mildew. Scrub the area with a combination of one part bleach and two parts water. Allow the carpet to air dry in direct sunshine. Throw away the vacuum cleaner bag as soon as possible. Its contents after the job can be a health hazard in the house.
Place the rug outside on a sunny day in the sunshine, and the sunlight will take care of a slight mold or mildew problem.
Apply undiluted white vinegar using a paintbrush or roller. This depends upon the size of the affected area. A sponge will work for small areas as well. Wipe the area clean until it is free from any mold, moss or mildew. Allow it to dry outside in the sun.