In warm areas, with high humidity as part of the normal climate, mould and mildew are to be expected. Where there is moisture and shade, mould and mildew find their way to surfaces that no one wants them on. When spring comes and it's time to pull out the patio furniture, there may be a certain amount of cleaning to do first. If a patio umbrella is stored while it was wet, it may have a new shade of colours when you pull it back out, like black and white. Fortunately there is a very simple fix to this very unsightly problem.
Brush away as much of the mildew as possible with a soft bristle brush. Be sure to do this outside as this can be quite messy.
Mix two cups of vinegar and two tablespoons of dish soap into a bucket of hot water.
Dip a soft bristle brush in the solution and use it to scrub away the mildewed area. Use more solution as necessary and scrub until all of the mildew is gone.
Rinse the area with clear water. Spraying it with a garden hose is a quick way to rinse it off completely.
Allow the umbrella to air dry in the sunshine.
Be sure that the brush used for cleaning is soft. Course bristles may cause tears. Bleach is highly effective in cleaning mould and mildew but isn't safe for dyed fabrics.