Here are some of the tips on how to clean a Patio Umbrella: Open the umbrella and lay down on a clean towel or protective surface, not letting the umbrella cover touch the ground directly. Hose top down. Lightly scrub with a clean cloth and mild, warm soapy water. Rinse again with hose. Stand umbrella back up in base or table and allow to dry before closing umbrella. Machine Wash - A Commercial Grade (Extra-Large) Washer can be used for deep clearing, such as those in Laundry-mats and hotels. This can be used for Olefin and Sunbrella fabric. Lesser grade fabric may not fair well. Remove umbrella cover from umbrella frame. Put umbrella cover in commercial washer and run at delicate cycle on cold with mild detergent. Remove umbrella cover and put back on umbrella to dry.