When cleaning out a fireplace, many people just put their wood ash into a bag or container and toss it in the garbage. But did you know that wood ash has many useful functions? You need to make sure that the ash you use comes from chemical-free wood, i.e. not from pressure-treated wood, painted or stained wood, charcoal, or commercial fireplace logs. If you know that the wood came straight from a tree, it’s safe to use. Just make sure you protect your eyes from ash dust and wear a mask if you need to, to keep from breathing in dust particles. Here are some of the most effective ways to use wood ash.
1. Raising Soil pH
If your soil is too acidic, you can use wood ash to raise the soil pH into a range that’s more acceptable for plants. You can also use small amounts in potted plants, particularly if the soil in your pots is full of acidic components such as peat moss or leaf mulch. If your plants are struggling with acidic soil, a little bit of wood ash watered into the soil can raise the pH enough to enable them to thrive.
2. Providing Minerals to Plants
Wood ash is full of calcium and other minerals that are helpful for plant growth. Particularly in soils that experience mineral depletion, wood ash can help restore minerals to the soil. Just be sure to check your soil pH so that you don’t raise it too much. You may also want to avoid wood ash around acid-loving plants such as blueberries, and you don’t want to use it around seedlings as it may kill them.
3. Deterring Insects
A light dusting of wood ash sprinkled around plants can be used to deter crawling insects such as snails and slugs. Just like diatomaceous earth or ground-up egg shells, the gritty texture will aggravate the soft bodies of crawling insects and keep them away from your plants. Just be sure to reapply after watering plants or after a rainstorm.
4. Making Soap
Wood ash has traditionally been used to create lye for soapmaking, as well as for making grits. Lye used to be made by cutting a tree in half lengthwise, burning out the middle, and running water through the ashes to create an alkaline lye solution. Soaking wood ash directly in water is easier to do to create the alkaline solution needed for soap making.
5. Melting Ice and Snow
The salts in wood ash will help melt ice without causing the corrosion that other salts can. It's darker color will also absorb heat from sunlight, further helping ice melt. It will also help provide traction for shoes and tires on slick, icy surfaces.
6. Getting Rid of Oil Stains
Wood ash can help remove oil and grease stains on cement, stone, and asphalt. Sprinkle wood ash on the spills, allow it to sit for a few minutes, then sweep it up and dispose of it in the trash. Repeat as necessary until the stain is gone.