What is Wood Ash Good For?

We may not burn as much firewood as we used to, but ash is still a great raw resource with a variety of benefits and uses around the home. Here are 8 ways you can use fireplace ashes around your home and garden.

1. Amending Soil and Boosting Your Lawn

Wood ash can be used to boost the pH of your lawn’s soil quickly—faster than limestone, since the ash is more water soluble. Start by getting your lawn or garden soil tested to determine its pH. Most lawn and garden soil does well at a pH level between 6.0 and 7.0. Higher than 7, and it’s considered alkaline. Lower than 6, and it’s considered acidic. If your soil is already between 6 and 7, there’s no need to change the pH. Certain plants, including some flowers and vegetables, thrive at different soil pH levels. For example, tomato plants need lots of calcium and potassium, and generally require soil amendments that provide high doses of these nutrients—something that an amendment of wood ash can deliver quickly, since it’s naturally rich in both of these nutrients and its water soluble. Since plant roots are inefficient at absorbing calcium and potassium from the soil itself, if your garden contains too acidic soil (which is low in those nutrients), you should amend it to promote healthy vegetable production in those plants.

Are Ashes Good for Plants?

Wood ash is also made up of other nutrients in smaller amounts, including aluminum, magnesium, phosphorus, and sodium. Some plants, such as alfalfa, hay, and corn, remove nutrients from the soil, and amendments or crop rotations are used to reintroduce them. Wood ash can provide those nutrients if needed. Check your plant and soil needs before arbitrarily adding wood ash around your property. Certain acid-loving plants like blueberries, azaleas, and rhododendrons won’t like having their soil made more alkaline. And adding loads of wood ash in any one spot is never a good thing.

2. Add Ash to Your Home Compost

A sprinkle of wood ashes can be added to your outdoor compost pile or indoor compost bin as one component of your household waste. A small amount with each layer of compost will add nutrients to the end soil or “compost tea.”

You can also make your own wood ash tea by soaking ashes in water for 4-5 days, and then applying that product to plant soil as needed. Three pounds of wood ash steeped and strained afterwards (like you’re making a big batch of wood ash tea) in a 30-gallon bucket of water can provide a benefit to certain plants during the growing season. (Apply judiciously—a little goes a long way. And make sure you’ve researched your plants’ specific alkalinity requirements in advance.)

3. Wood Ashes for Cleaning

Looking for a cost-free cleaner for glass and metal? Wood ashes, mixed with a bit of water to form a paste, can be used as a mild abrasive to buff up tarnished metals, clean dirty glass, and even remove adhesives and sticky residue. Apply the paste with a cotton cloth while wearing gloves to protect your skin. Try in a small spot at first to test the results.

4. Make Soap at Home

The first soaps were made on homesteads by combining water and wood ash to make lye, a necessary component of soap. Ashes from burned hardwoods (such as ash, hickory, or beech) are used for this purpose since they contain enough potassium to produce lye. Careful production can yield homemade soap from what you’d otherwise throw away, though with a bit more effort than it takes to buy a bottle or bar. (If going the homemade route, follow instructions from a reputable source and make sure to wear protective gear to avoid burns.)

5. Keep Harmful Bugs Away

Wood ashes can be used to deter pests like slugs and snails, and even to repel ants. Sprinkle a small amount or ring around susceptible plants and reapply after the rain washes the ash away.

6. Add Traction to Slippery Walkways

Like gravel on snow-covered streets, wood ash can be applied to provide traction underfoot. You can even keep some in a closed metal container in your car or truck to use in an emergency to get out of a slippery spot. (Just be careful not to track the ash back into the house on your soles.)

7. Soak Up Driveway Spills

Changing the oil on your car? Or just spilled something that might stain? Use wood ash to absorb the spill. The driveway’s dark asphalt will mask the ash’s color, and the ash’s absorbing properties should allow you to sweep up the spill afterwards.

8. Fire Control

If you’ve ever “smothered a fire” at a campsite by shifting ashes over hot coals, you know that ash can form a great air-tight barrier that will help extinguish the flames. Wood ashes can help put out a fire when a fire extinguisher, soil, or sand is unavailable. Always extinguish a fire completely and make sure no embers are left smoldering as they could reignite. A final check for any hot spots (hover your bare hand in several spots over the wet embers) ensures you won’t have a fire reignite later.