Most people think of paint stripping and graffiti removal when they think of pressure washing. It is really good for those things but you can also use a pressure washer around the exterior of your home such as roofs, siding, brick, driveways, decks, and patios. Power washing can really be a benefit. However, if not done properly it can cause damage, including exterior plants. Many power washing chemicals claim to be environmentally friendly but precaution still needs to be taken in order to wash effectively around them. The more pure water and soil that gets into them the healthier your plants will be. There are some instances where you may need to cover them, though.

Using Bleach

When cleaning exterior surfaces, sometimes bleach is used on surfaces that need the extra oomph. Usually the bleach solution is mixed with a 3:1 ratio of water to bleach. This mixture makes it safer. Bleach does break down into salts, though, as it dries and it can be dangerous to plants. Plants need to absorb water and high salinity makes this difficult and often leads to plant death if it’s not rinsed away. 

The best way to protect plants is to make sure you water your garden thoroughly both before and after pressure washing. This will allow for maximum dilution of the bleach solution and decreases the bleach concentration in the garden. 

Cleaning Detergents

Detergents are also mixed with water. This solution is usually a 10:1 ratio. Like bleach, even though they’re diluted with water, they still can be harmful to plants. If allowed to sit for long periods of time, they can cause brown spots on certain plants. You can minimize brown spots by taking the same precautions that you would take when using bleach. The more water that is added to the plants, the more diluted these cleaning agents become and the less they’re absorbed. 

Prevent the Chemicals From Getting To Plants

The best way to keep plants healthy is to remove them from the immediate area that is being pressure washed. This is simple when you’re dealing with potted plants such as those on some patios or porches and hanging plants. Sometimes you can’t remove them, though, so the next best thing would be to cover them when you’re working in that area but not all day. When you’re done working in those areas it’s best to uncover them so that the excess heat doesn’t damage them. Covering plants reduces chemical runoff.


When you power wash natural wood siding you usually have to use a sealant to protect the wood after cleaning. Sealants are more dangerous to plants than bleach or cleaning detergents are. If it will seal the wood on siding, it will definitely seal plants and prevent them from absorbing the water and nutrients they need. Spraying them afterwards won’t help and eventually they will die so it’s best to get them covered so you don’t have to worry about them.