Why You Should Wash Your Flower Pots
Wrap up your container garden season with some TLC for pots: wash, sanitize and drip dry.
You can’t beat container gardens for filling summer with color. I usually plant at least a dozen pots to brighten outdoor living areas.
At the end of the growing season, after tossing spent annuals onto the compost pile, I set aside a day for pot washing. I didn’t always wash my pots. For years I simply emptied and stacked them in a corner of the garage until spring. Then one spring all of my geraniums died very quickly. This included newly purchased plants, as well as ones I had overwintered for years (the older plants opened flowers the size of softballs). I suspect I had bacterial blight, a deadly disease for geraniums. That was the first year I washed all my flower pots at the end of the growing season, and I’ve been doing it ever since.
The top reason to wash your pots is to disrupt disease, pest and weed issues. Many of these problem organisms survive in soil or on pot surfaces, hidden away in mineral deposits or plant and soil debris. Washing and disinfecting pots eliminates the threat of many potential problems.
Some gardeners wait to wash pots in spring, but if you wash at the end of the growing season, everything goes into winter storage clean. It also means you can grab pots at any point during the coming months knowing they’re good to go. I like being able to tackle earliest spring planting efforts — usually perky pansies and lettuce — with pots that have a clean bill of health.
Prep a Washing Station
Start the process by filling a large container with warm soapy water. I use a plastic wash tub, but an oversize lidded storage tub would work, too. On occasion I've also lined a laundry basket with an old shower curtain. Dish soap creates sufficient cleaning power to remove dirt. Grab a scrub brush or sponge to remove dirt and debris from containers. I upcycle kitchen scrub sponges that are past their useful kitchen life to use as pot scrubbers.
To remove mineral deposits on pots (those white rings around pot rims or the inner upper edge), use steel wool or a wire brush on clay pots or a heavy duty non-abrasive scrub sponge on plastic pots. Rubber gloves are a must because after washing pots, you’ll want to sanitize them in a bleach bath.
Sanitize pots by soaking for 10 minutes (minimum) in a bleach solution that’s 1 part household bleach to 9 parts water. The easiest way to make this solution is by the gallon. To get the proper solution concentration, mix 1-1/2 cups of unscented household bleach with 14.-1/2 cups of water. An easy way to do this is to prep your solution in a 5-gallon bucket, adding 7-1/2 cups of bleach (just shy of 2 quarts) and topping that with water until the bucket is full. Your solution should have a distinct bleach odor.
Pots need to soak in this solution, so you need a large container. I use an extra-large wheeled storage tub for my sanitizing basin. The biggest containers can lay in the tub on their sides, and I turn them occasionally to make sure all surfaces soak in the bleach water.
One quick tip: By the time garden season is over in the Mid-Atlantic, water coming out of the hose is bracingly cold. Since I usually do this on a chilly day, I skip the hose and haul buckets of hot water to fill my washing and sanitizing baths.
Wash pots, saucers and anything else you might have on hand that’s in your plant growing arsenal. I fill the bottoms of my containers with empty plastic juice bottles, which I wash, sanitize and recycle from year to year. I also wash and sanitize a variety of smaller pots just to have them on hand for houseplants, herbs or other growing projects I tackle over winter. Birdbaths also get a dip in the wash and sanitize tubs.
Invert to Drip Dry
As you finish washing pots, invert and stack so they can drip dry. The bleach solution is not concentrated enough to damage turf if that’s the only place you have to drain pots. I usually work on a patio or porch. Once pots are dry, stack and stash them for the winter.
Dispose of your bleach solution by pouring it on a driveway or patio. On a sunny day, the sun quickly evaporates the solution and the bleach dissipates into the air. The solution isn’t strong enough to kill vegetation, but it may harm soil organisms and microorganisms. I often pour it where I don’t have plants growing, like the gravel strip behind the shed. If you don’t have a good place to dump it, add aquarium tap water dechlorinator, following the directions on the bottle.