Gazebo fabrics do require maintenance, and taking proper care can essentially prolong the life of your model. Instead of leaving the canopy outside and risk weather damage, you should take it off and store it in a clean and dry place. Leaving it out in harsh sunlight or rain can cause the fabric to wear out sooner. Before packing the gazebo up for the season, make sure that it is clean and intact. It is advisable that you clean the fabric before putting it away in storage.
For cleaning and maintenance, you can wash and scrub the canopy top using a sponge soaked in water and detergent. Hand washing the canopy is recommended instead of washing it in a machine. Also, you can get it dry cleaned if it has any stubborn stains.
Make sure the canopy has fully dried before packing it up. You can also use a fabric spray to keep the canopy as good as new for a long time. Slacking off on maintenance will make the fabric wear out quickly and require canopy fabric repair or change.