This week I want to take a look at another common organic fertilizer called Blood Meal. Blood meal is a dry inert powder made from animal blood and used as a high nitrogen organic fertilizer. It is also used as a high protein animal feed from dogs and cats to fish. It is a slaughterhouse by-product of our meat industry and the most common source is from cattle, however in some areas it is made from hogs. 

Blood meal is primarily considered a nitrogen source however it may contain small amounts of other nutrients and trace minerals. A analysis can be as high as (N-P-K) of 13-1-0.06 but most sources just list blood meal as a 12-0-0. 

Some types of blood meal are fortified with iron (Fe) and can lead to iron toxicity in the garden. The iron naturally found in blood meal is in what is known as the Ferric oxidation state or form and is the type of iron that binds to organic matter and that plants prefer. Best to avoid brands with added iron. 

When microbes breakdown the blood meal, the nitrogen (N) is released in the ammonia form (NH4+) which is preferred by perennial plants. Note: The nitrate form of nitrogen (NO3-) is what weeds prefer. 

Many myths persist that blood meal and bone meal contain mad cow disease (BSE) bovine spongiform encephalopathy. According to research, the prion protein is not found in blood, bone, or milk, hence it has never been found in blood meal or bone meal. 

Usage varies from 7 pounds per 1,000 square feet to 25 pounds per 1,000 square feet. The blood meal can also be dissolved in water and used in this way to quickly add nitrogen to the soil. 

In warm moist weather one needs to be careful as the blood meal can breakdown so quickly that it can burn plants. Blood meal encourages fast leafy growth and too much at one time can make plants more susceptible to attack by insects and disease. It is always better for the soil, the microbes and plants to have several light applications of fertilizers spread out over a large period of time rather than one heavy application. 

Many animals (carnivores) naturally eat blood as part of their diet hence are attracted to blood meal. This includes pets (dogs and cats) to raccoons and other animals. One website for pets indicated that it can make pets sick. My dogs over the years never had any problems and just thought it was a tasty treat. 

SUMMARY: 

Blood meal is another tool in a gardeners toolbox and is a great way to quickly correct nitrogen deficiencies or help out in a compost pile. 

PROS: 

– good source of nitrogen 

– relatively inexpensive 

– good availability 

– available in bags or bulk 

– reported to repel rabbits and sometimes deer 

-fast acting 

– easy to use 

– often used in compost piles as a nitrogen source 

– can be applied dry or as a liquid 

– low salt 

CONS: 

– may burn plants 

– may attract carnivores like dogs, cats and raccoons 

– short lived in the environment 

– may be dusty 

– not a complete fertilizer 

– too much can cause nutrient tie-up problems.