How to Use Wood Ash As a Fertilizer

Wood ash also provides calcium to plants.
Wood ash also provides calcium to plants. (Image: Susie Cushner/Digital Vision/Getty Images)

Wood ash is the powdery substance leftover after burning firewood. While most people dispose of the ash in the trash can, others place it in their garden to use as a fertilizer. While wood ash should not be used in large quantities, small amounts can adjust the soil acidity and provide potassium. According to the University of California, wood ash contains five to seven percent of potassium and approximately two percent of phosphorous. The best time to spread wood ash as fertilizer is in the fall.

Things You'll Need

  • Garden tiller
  • Broom
  • Shovel
  • Wood ash
  • Bow rake
  • Garden hose

Video of the Day

Position a garden tiller at the edge of the desired planting area and set the blade depth to between five and six inches. Turn the tiller on and push it over the chosen area to dig up the soil.

Sweep the ashes out of your fireplace, or use a shovel to collect them from outdoor wood-burning pits or fire pits.

Spread the ashes over the tilled area at a rate of five to 10 lbs. per 100 square feet of space.

Rake the planting area with a bow rake to mix the wood ash into the soil well.

Allow the planting area to sit undisturbed for at least three to four weeks before planting in it.

Tips & Warnings

  • If desired, you can fertilize plants that are already in the ground by applying the wood ash on top of the ground near the plant. Spread it in a circle approximately six to 12 inches from the base of the plants. Rinse the leaves of the plants with a garden hose after the wood ash application.
  • Do not apply wood ash as fertilizer more than once per year.


Promoted By Zergnet

You May Also Like

Is DIY in your DNA? Become part of our maker community.