Bone meal for plants is made by cleaning animal bones, then boiling or steaming them to remove remaining organic material, drying them, and grinding them into a fine powder. It is used as a slow-release fertilizer because it supplies phosphorus and calcium to soil over time.

How it’s made

  1. Bones are collected, usually as a byproduct of the meat and rendering industries.
  1. They are cleaned thoroughly.
  1. The bones are boiled or steamed to remove leftover tissue and fats.
  1. After drying, the bones are crushed and ground into a powder.

Why gardeners use it

Bone meal is valued for its phosphorus and calcium, which support root development, flowering, and overall plant strength. It releases nutrients slowly, so it works best when mixed into soil before planting or placed in the planting hole.

A few cautions

Bone meal is not a complete fertilizer, so it should not replace a balanced soil program. It also works best in slightly acidic soil, since it breaks down more effectively there.