Lawn furniture deals with an onset of moisture, excessive heat, rain and any other damaging elements that Mother Nature can throw at it. This will quickly cause the fabric of the lawn furniture to develop mildew. Unlike mold, black mildew will not deteriorate the fabric but it will leave unsightly and possible permanent stains on the fabric lawn furniture. Fortunately, you can remove the black mildew stains using inexpensive products found in many households.
Place the lawn furniture on top of a tarp spread out on flat ground. Brush the surface debris off the furniture with a scrub brush or cloth.
Pour 1 cup cold water in a bucket. Add 1 cup of clear ammonia to the water and stir with a spoon for several seconds.
Put on your gloves. Saturate a cloth in the diluted ammonia mixture. Hold the soggy cloth over the bucket and wring out the excess liquid.
Rub the black mildew stains gently for several seconds until you have saturated that area of the fabric with the cleaning solution.
Let the mixture soak on the lawn furniture fabric for 5 minutes. Wet a clean cloth in cool water and blot the mixture off the furniture.
Repeat the process until you have removed the black mildew stains. Place the fabric lawn furniture in a sunny location to air dry for several hours.