How to Use Ash for Compost

Wood ash is a valuable addition to compost.

Wood ash is a valuable addition to compost.

Ash from your fireplace or outdoor fire pit can be a useful amendment to your garden. In its raw state, ash can discourage insects living in the compost pile from migrating to the rest of your garden. It can also add lime and potassium to the soil. When used in compost, ash adds valuable nutrients without changing the pH of the soil. The exact nutrients depend on the type of wood that is burned. Layering wood ash into the compost pile also helps control odors and neutralizes the pH of the compost. (See References 1)

Build Your Compost Pile

Choose a location for your compost bin or pile. Ideally, this location should be shaded and near a water source. This will prevent the compost from drying out in hot weather. If you are building your compost pile directly on the ground, be sure you have a 3-foot by 3-foot space available.

Layer 6 inches of brown, carbon-rich materials such as dry leaves or twigs in the compost bin or on the ground.

Add a 3-inch layer of green, nitrogen-rich materials such as grass clippings or kitchen scraps.

Sprinkle a thin layer of soil or finished compost over the pile.

Add a thin layer of ash to the compost pile or bin.

Repeat these layers until you run out of compost materials.

Use the hose to spray down the entire compost pile. Do not saturate the pile. It should be about as moist as a damp sponge.

Maintain Your Compost Pile

Use a shovel or pitchfork to turn the compost weekly. Move materials from the outside of the pile toward the center, and materials from the center toward the edges.

Spray down the compost pile with water if it is too dry.

Cover the bin or pile with a tarp -- and secure the edges with rocks to prevent heat and moisture loss -- in the event it dries out quickly.

Continue to add compost materials and ash to the pile as you accumulate them. Turn the pile thoroughly after you add new materials to ensure they are well-mixed.

Items you will need

  • Compost bin or pile
  • Shovel or pitchfork
  • Carbon-rich compost material
  • Nitrogen-rich compost material
  • Soil or finished compost
  • Wood ash
  • Hose and water source
  • Tarp and large rocks (optional)


  • Insects, grubs and other creatures are an integral part of the compost process. If your compost bin or pile is near your garden and you are concerned about those creatures migrating out of the compost, spread a ring of ash around the pile. Most crawling creatures will not cross the line. (See References 2)


  • Do not use charcoal ash in your compost pile. It may contain elements that are harmful to certain plants. (See References 3)
  • Do not use ash from black walnut wood. It contains chemical elements that are harmful to plants. (See References 3)

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About the Author

Tricia Ballad is a writer, author and project geek. She has written several books including two novels, teaches classes on goal setting and project planning for writers, and loves to cook in her spare time. She is living proof that you can earn a living with a degree in creative writing.

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