Why Does My Patio Turn Green? Black?

No one likes the three M’s: mold, mildew and moss. But, they happen in more places than we often realize. One of these places: your patio. In fact, mold, mildew and moss may be the reasons why your patio is turning green or black. Unless you have flagstone pavers that are greenish gray, which then the colors will be brought out when it rains, it’s probably one or all of the three M’s responsible.

Patios are durable and long-lasting, but they aren’t perfect. If your patio is shaded and doesn’t get a lot of direct sun, it’s more at risk for developing moss and algae. This is especially true when New Jersey has wet, rainy weather for days at a time. You may start to see weeds and moss growing in between the pavers or stones, and this can quickly take over, especially if you haven’t power washed the patio in quite some time. Thankfully, a bit of maintenance goes a long way in protecting your patio.

Here’s what to do.

Power Wash Your Patio

The first thing you’ll need to do is create a clean slate to work with. Power wash the patio, remove existing weeds and scrape off moss with a flat head screwdriver. For many people, power washing does the trick, but it sometimes isn’t enough. If this is the case with your patio, follow the next tips.

Pour Sand in the Paver Joints

Apply a thin layer of polymeric sand in between the pavers and make sure it gets down into the joints. Remove the sand from the top of the pavers since it can leave behind stains. The purpose of the polymeric sand is to inhibit weed growth and prevent bugs from making their home in between the stones.

Apply a Vinegar Solution to Kill Weeds

If weeds do pop up over the spring and summer, and we can assume they will, you’ll need to take action. You don’t want to use harsh chemicals that could harm your landscaping or garden, so use a vinegar solution instead. Try ½ cup vinegar and ½ cup borax, or add 1 teaspoon of vinegar to a spray bottle, along with 1 teaspoon of dishwashing soap. Keeping on top of weeds will prevent the problem from spreading into moss, mold and mildew.

By following these tips, your patio will be clean enough to eat off of!