A common sight in areas that receive plenty of rainfall, moss can be a nuisance. Not only is it a slip hazard, but over time it can open the door to damage to walls, roofs and patios. You can kill it using something you probably have in your pantry: vinegar.
Used as a condiment in the kitchen, the acetic acid found in vinegar also makes it an effective household cleaner. Most forms of vinegar contain between 4- and 8-percent acetic acid. This formulation is strong enough to damage and kill plant and fungal growth, including moss. Use white vinegar to kill moss; red or cider vinegar can stain the objects you are trying to clean.
To kill moss growing on brick, siding or tile, combine two parts vinegar and one part water. Soak the moss with the mixture, then let it sit for about 40 minutes. Rinse the moss and surrounding area with water to wash away the vinegar solution. If any moss remains, either blast it away with your garden hose or a power washer, or scrape it away with a broom.
While vinegar is a good natural option for killing moss, it does have some drawbacks. It works well on small, isolated patches of growth, such as those on a brick wall or stone patio. Sometimes more than one application of the vinegar solution is needed to completely kill moss. Vinegar doesn't provide any protection against future moss growth, so you could have to use it over and over again.
If you know that moss will return to a certain spot on a wall or deck, wash it down with a solution of one part vinegar to one part water every couple of weeks. This kills any spores before they have a chance to establish and grow. If you have larger patches of moss, especially on your roof, use a moss-killer, such as copper sulfate, to get rid of it. Not only will it kill moss more effectively, but it also provides lingering protection against moss returning.