After more than 56 years in the carpet and upholstery cleaning business, I’ve learned that when it comes to outdoor cushions, an ounce of prevention really can be worth a pound of cure.
I’ve had outdoor cushions at homes I’ve owned in Massachusetts, on Cape Cod, and here in Florida. One thing I’ve noticed over the years is that the climate can make a big difference in how quickly outdoor cushions develop mold, mildew, algae and that familiar musty odor.
Why Do Outdoor Cushions Develop Mold, Mildew and Algae?
People sometimes wonder how an outdoor fabric such as Sunbrella can develop mold or mildew. After all, many outdoor fabrics are made from solution-dyed fibers that are highly resistant to moisture and staining.
The important thing to understand is that the fiber itself isn’t necessarily what is holding the moisture.
Outdoor cushions are constantly exposed to dirt, dust, pollen, leaves, bird droppings, body oils and other organic material. Those contaminants can accumulate on the surface of the fabric and hold moisture. When the cushion stays damp long enough, the combination of moisture and organic material can create an environment where mold, mildew and algae can develop.
And this is where prevention becomes so important.
If you’ve ever wondered why fabrics can develop a different or musty smell after becoming wet, you may also want to read my Ask Alec article Why Does Carpet or Upholstery Smell Different When It Gets Wet?
My Experience With Outdoor Cushions in Massachusetts and on Cape Cod
When I lived in Massachusetts and on Cape Cod, I generally kept my outdoor cushions stored inside the garage when I wasn’t using them.
During the warmer months, it is easy to think that outdoor cushions should simply be left outside. You may have a beautiful sunny afternoon with warm temperatures, but the conditions can change considerably once the sun goes down.
Cooler nighttime temperatures, dew and moisture in the air can leave outdoor cushions damp. If that happens night after night, the cushions may not have enough time to completely dry before they are exposed to moisture again.
Over time, that repeated exposure can contribute to mold, mildew, algae and musty odors.
So what did I do?
I brought the cushions inside.
I would take them out when I was going to use them and put them back into the garage afterward.
I realize that most people aren’t going to carry their outdoor cushions into the garage every evening. But if your goal is to prevent mold and mildew rather than deal with it later, keeping the cushions dry and protected when they aren’t being used is one of the most effective things you can do.
What About Outdoor Cushions in Florida?
My experience with outdoor cushions in Florida has been somewhat different.
Florida certainly has plenty of humidity and rain, particularly during the summer. But during much of the year, outdoor cushions can dry very quickly because of the combination of warm temperatures, sunshine and air movement.
A typical summer afternoon rainstorm may soak everything, but once the rain stops and the sun comes back out, outdoor surfaces can dry surprisingly quickly.
That doesn’t mean outdoor cushions in Florida won’t develop mold, mildew or algae. They certainly can. Eventually, dirt and organic material can accumulate, and cushions that remain outdoors can become musty or develop visible growth.
But in my experience, the conditions can be different from what I experienced in Massachusetts and on Cape Cod, where cool, damp nights could keep outdoor cushions moist for much longer.
The Best Solution? Prevent the Problem
If you want to minimize the chance of mold and mildew developing on your outdoor cushions, my first recommendation is simple:
Keep them clean and keep them dry whenever possible.
If you aren’t using the cushions, storing them in a dry garage, shed or other protected area can help.
If you don’t have a place to store them, at least try to avoid leaving them wet for extended periods. After rain, give them an opportunity to dry completely before covering or storing them.
And remember that a cushion doesn’t have to look dirty for it to have accumulated pollen, dust, oils and other contaminants that can hold moisture.
But What If Your Cushions Already Have Mold, Mildew or Algae?
That’s when the situation becomes more complicated.
You have several options, but outdoor cushions should be cleaned with some care. The cleaning method needs to take into consideration both the fabric on the outside and the material inside the cushion.
If you aren’t familiar with the fabric or aren’t sure how the cushion should be cleaned, I recommend having a professional cleaning company handle the job.
A professional who regularly cleans outdoor cushions should understand the differences between outdoor fabrics, the types of contamination commonly found on them, and how to clean them without unnecessarily saturating the cushion.
If You Decide to Clean Them Yourself
If you decide to tackle the job yourself, always start by checking the manufacturer’s cleaning recommendations and testing an inconspicuous area of the fabric.
For fabrics that are confirmed to be compatible with chlorine bleach, a properly diluted bleach solution can be effective against mold and mildew. Use only the type and concentration recommended for the particular fabric and cleaning situation, and never mix bleach with ammonia, acids, vinegar or other cleaning chemicals.
I also recommend working in a shaded area while applying the cleaning solution. Direct sunlight can accelerate the breakdown of chlorine bleach, reducing its effectiveness before it has had enough contact time to work.
Allow the cleaning solution appropriate contact time according to the product and fabric manufacturer’s directions. If necessary, gently agitate the surface with a soft-to-medium nylon brush.
Then rinse the cushions thoroughly with a garden hose.
I would not recommend using a pressure washer on outdoor cushions.
A pressure washer can force water deep into the cushion and potentially saturate the foam or other interior materials. The outside of a cushion may appear clean while the inside remains excessively wet.
That’s exactly the situation you want to avoid.
Before You Grab the Garden Hose, Pressure Washer or Bleach
Drying the Cushions Is Just as Important as Cleaning Them
Once the cushions have been thoroughly rinsed, the next step is to get them dry.
This is particularly important because cleaning a cushion and then leaving it wet can create another moisture problem.
Place the cushions where they can dry thoroughly. Sunshine and good air circulation can help, and a fan can accelerate the drying process.
If the cushions have zippers, you can also inspect the interior once the outside has been cleaned and dried.
Look for any visible signs of mold or mildew and pay attention to whether there is still a musty odor coming from inside the cushion.
If contamination has penetrated into the interior material, simply cleaning the outside fabric may not completely solve the problem. At that point, professional cleaning may be the better option.
The Bottom Line From Alec
After 56 years in the carpet and upholstery cleaning business, I’ve learned that preventing a cleaning problem is usually easier than correcting one after it has become established.
Outdoor cushions are a perfect example.
If you live in an area where outdoor cushions are exposed to damp nights, dew and prolonged periods of moisture, bringing them inside when you aren’t using them can make a tremendous difference.
I did exactly that with my own cushions when I lived in Massachusetts and on Cape Cod.
Here in Florida, I’ve found that I can leave my outdoor cushions outside for much longer because the conditions are different. But even here, they eventually need attention.
So remember the old saying:
An ounce of prevention is worth a pound of cure.
When it comes to outdoor cushions, keeping them clean, dry and protected when possible can save you from having to deal with mold, mildew, algae and musty odors later.
And if your outdoor cushions already have a problem, don’t assume that the fabric is ruined. In many cases, professional outdoor cushion cleaning can make a significant difference.
Be sure to vist our page on our website about Outdoor Cushion Cleaning