Acrylic fabric, such as Sunbrella and other synthetic materials, does not promote mildew growth-however, mildew could grow on embedded dirt and other foreign substances, such as tree sap, that are not removed from the fabric. Sunbrella recommends the following steps to clean mildew or other stubborn stains from Sunbrella fabric*.
Mix 1 cup bleach and ¼ cup mild detergent in 1 gallon of water.
Fill a spray bottle with the solution and spritz the soiled area until it's saturated.
Let the fabric soak for 15 minutes, then use a sponge, clean towel, or soft-bristle brush to gently scrub the stain.
Rinse thoroughly with clean water or wash the canopy in the washing machine and allow it to completely dry in the sun.
* If your umbrella is made by another manufacturer, check the manual or tags first to see if the material is bleach-safe.
Aluminum pole: Most modern patio umbrella poles are made of aluminum and won't rust, Taylor says. However, the hardware, screws, and rivets can be susceptible to rusting. Similar to the canopy, you want to keep the pole as dry and dirt-free as possible. It's as easy as wiping it down with a damp cloth. Sticky spots might need a little soapy water, followed by a rinse and thorough drying. Never use an abrasive or corrosive cleaning product, such as bleach or ammonia, which can damage the finish.
If you notice calcium buildup from hard water on your patio umbrella frame, use a solution of 1 part white distilled vinegar and 9 parts water to help remove it. Before you apply your solution, test it in an inconspicuous area of the frame to make sure it doesn't discolor the finish.
Wood pole: For most wood umbrella poles, a mixture of mild dish detergent and water along with a cloth or soft-bristle brush will suffice to clean it. If there are spots with mildew, use a bleach-based household cleaner and a plastic pot scourer to remove them, then rinse thoroughly.
Wood can show wear over time. To help boost its luster and durability, oil unsealed wood annually with a wood protector or synthetic penetrating decking oil.
General Patio Umbrella Maintenance Tips
Now that your patio umbrella is looking fresh and clean, take a few extra steps to help keep it that way longer.
"If you're a patio umbrella fanatic like me, keep it stored anytime you're not using it," Taylor says. Keep it protected from the elements indoors, as in a shed.
If you prefer to leave your umbrella out for the season, make sure to close it when not in use (wind damage is the most common source of a broken frame) and get a slipcover to protect it.
To avoid staining, don't allow mildew or oily tree leaves to stay on the umbrella for long periods of time.
After rain showers, check to make sure water isn't pooling inside the stand, especially if you have a wood pole umbrella. Over time, the moisture can rot the wood, Taylor says.
If the canopy is looking worse for wear, don't toss out the frame with it. You might be able to find a replacement canopy for much less than it'd cost to buy a new set.