Disadvantages of Using Blood Meal Excessive nitrogen is sometimes the culprit when plants are not producing as many flowers as you would like. Excessive amounts of nitrogen can even burn plants or, worse yet, kill them. To avoid such problems, follow the application instructions on the package of blood meal.

Why use bone meal for plants? Bone meal is a great fertiliser for a few key reasons: The first is that it's a great source of Phosphorus which is used by new plants to produce strong roots and so is great for root vegetables such as onions, garlic, carrot and parsnip.

And although bone meal and blood meal sound similar and are both organic fertilizers, they differ in the nutrients they contribute to help plants grow. Blood meal is high in nitrogen while bone meal provides varying amounts of phosphorus and calcium.

Blood meal is a dry, inert powder made from blood, used as a high-nitrogen organic fertilizer and a high protein animal feed. N = 13.25%, P = 1.0%, K = 0.6%. It is one of the highest non-synthetic sources of nitrogen. It usually comes from cattle or hogs as a slaughterhouse by-product.