Blood meal has many uses in the organic garden. Made of blood that has been dried to a powder form, it acts as a quick source of nitrogen, a necessary element to support a plant’s growth. In fact, dried blood has been used as a soil amendment since ancient times. Blood meal can also be used as a compost activator, or to repel some common garden pests.
For the best quality compost, it’s important that there is a good balance of both nitrogen and carbon. If your compost is heavy on brown, carbon-rich materials such as dry leaves and twigs, adding blood meal will increase the nitrogen levels, allowing organic material to break down more quickly. Sprinkle between layers of brown material, keep pile moist, and turn frequently.
Nitrogen in the soil aids a plant in the production of its foliage, which it then uses to produce food. Blood meal is high in nitrogen, making it a particularly effective fertilizer for all plants, but especially those that are grown for their foliage. Try using blood meal in your vegetable garden to stimulate the growth of lettuces and other leafy greens. There are a few caveats, however. Use blood meal according to the directions on the package; too much nitrogen in the soil, while encouraging foliage, can discourage the production of flowers or fruit at best and at worst, can burn a plant’s roots. Blood meal also increases soil acidity. Don’t use blood meal on seedlings or on any members of the legume family.
It’s believed that a sprinkling of blood meal can be used as a repellant for common garden pests such as deer, moles, rabbits, and squirrels. Rain will wash it away, so it will need to be reapplied regularly or placed around problem areas in covered containers that will still allow the scent to be released. The smell of blood meal may be attractive to some other animals, however, such as dogs, cats, opossums, and raccoons, so test in a small area before widespread applications.