Hello Fellow Readers, A few weeks ago, we spoke about how to evict ants from a natural stone patio without spoiling the charming moss in the joints (link below). The topic brings to mind how best to clean patios and walks without damaging the stone or plants; one of my nagging dilemmas. I adore the moss between the joints, but the presence of moss can go hand in hand with mildew, which is slippery when wet.
I’ve used a power washer which is risky in terms of damaging stone. Then there’s the ick factor of scum kicking back at you. More than that, there’s the likelihood of kicking out the sand and green goodies in the nooks and crannies. My power washing outcome was clean centers of each stone while the areas near the joints remained green. Not so pretty. So, I sought out other remedies – all are best to do on cloudy days so the cleaning solutions won’t dry on the surface. Of course, first, blow off the surface dirt.
Folks swear by a product called Wet and Forget. As the name touts, all you do is spray it. The ingredients are water, benzyl ammonium chloride, and ethanol which are safe for plants. I hate to break the news, but you need to scrub the patio for it to be effective. Here are other remedies to try:
1. Good old soapy water made from 3 tablespoons of biodegradable dish soap, free of harmful bleach or fragrance, to one gallon of warm water can do the trick. Be sure to use a plastic or natural bristled deck brush; never a metal brush, as it will scratch. Keep in mind plants have a wax covering that is affected by soap. After scrubbing, dilute the soapy water with the garden hose to keep your plants happy.
3. They say you can use 2 cups of oxygenated bleach to a gallon of warm water, which, unlike chlorine bleach, doesn’t have a toxic smell and is safe around pets. Oxygenated bleach is made of sodium carbonate (soda ash) and a dry form of hydrogen peroxide. The challenge is finding one without harmful additives.
There’s a product called Stain Solver with no added fillers or fragrances. Spray the mix with a garden hand pump sprayer and allow to soak for ten minutes before scrubbing. Then rinse with water. You can also use the oxygenated bleach and water combo to clean wood or composite decks, even tile grout indoors. Some reviewers said it might hurt moss, so do your best to avoid the fuzzy.
4. I read 4 tablespoons of baking soda (sodium bicarbonate) dissolved in a quart of warm water is safe on wood, concrete, natural stone and won’t harm plants. They say baking soda helps lessen the impact of powdery mildew and several other fungal diseases. Sounds promising! After you scrub, I bet you’ll need to rinse thoroughly, so no white residue is left behind.
On a rainy day, I gave the baking soda option a spin, and here’s the outcome:
While the half-hour test run proved encouraging in terms of outcome, multiplied by the square footage, I figure the total task will take about six to eight hours. Oh my!
Link to column Ants be Gone
Column Updated 3/28/22