Mildew is a growth formed by mold that is black or white and develops when something is damp or wet for a prolonged period where air circulation is poor. Mesh lawn chairs can develop mildew if the chairs have been left out during a rainstorm and the weather is humid. The chairs haven't thoroughly dried, causing patches of mildew. Don't throw away your lawn chairs. Instead, clean the mildew with common household products.
Brush off any loose mold or mildew from the mesh lawn chair.
Mix a small amount of mild detergent and half a cup of bleach into 1 gallon of hot water.
Scrub the mildew off the mesh with a clean sponge dipped into the bleach mixture until all traces of the mildew are gone.
Rinse well with a water hose. Let it dry thoroughly in the sun.
Spray with a mildew-protection spray or water-repellent spray once the mesh lawn chair is dry. Follow the directions on the container for proper usage.