It does get mold/mildew.
Chuck:I would disagree. Sunbrella does get mold/mildew and then you need to wash them and retreat the fabric.Take a look at Bottom Siders here on the website. We cover ours with Terry Cloth covers. Keeps dogs prints off them and they are cooler to sit on in the warm summer heat. To make the covers we went to Costco and purchased 4 towels for about $5 ea. Used velcro on the end that fits against the bulkhead. Take them off every weekend (if they are dirty) and wash them with our regular wash.When the weather is foul, you DO NOT use the covers. They clean up easy and DO NOT absorb moisture. They are not cheap, but they are not cheap either!