Blood vs. Bone meal
Natural soil amendments, blood meal and bone meal are a must to any organic gardener to ensure a rich nutrient soil base, adding the much needed nitrogen and phosphorous to encourage healthy, lush full plants. Blood meal is dried and powdered animal blood; it increases soil nitrogen levels. Bonemeal is ground animal bones; it increases soil calcium and phosphorus levels.
Bone Meal: Phosphorous for Root Development

Bone meal is made from steamed and then crushed animal bones. It is high in Phosphorous which is important for root development and flower growth. Bone meal also contains calcium and nitrogen, these are also very beneficial to plant growth. As bone meal is absorbed at a slow rate it is important to follow directions on your box/bag as to not cause any burning to the plants roots or fresh growth.
Bone meal has become a popular choice for pairing with bulbs and roses as both of these flourish with an extra boost of phosphorous. When planting bulbs in the fall add bone meal to soil in the hole with bulb and then backfill with rest of soil. Bone meal is also a great boost in the early spring for other plants just coming out of dormancy, mix bone meal to the first couple inches of soil in garden.
Blood Meal: Nitrogen for Healthy Growth

It may sound a little macabre, but blood meal is a natural way to boost all-important nitrogen levels in the soil. Without nitrogen, plants simply can't grow. Blood meal is one of the richest non-synthetic sources of nitrogen, which is a crucial component of plant cells and one of the basic components of chlorophyll, the substance that helps plants convert sunlight into sugars. It helps plants grow healthy root systems and produce green foliage more rapidly, making them more resistant to pests and diseases.
Want big, overflowing baskets of fruits and vegetables from your organic garden? Blood meal helps increase plants' yield, adding lots of leafy green growth. This makes it a great fertilizer for nitrogen-hungry greens like lettuce, Brussels sprouts and kale.
Blood meal can also be used to balance the nitrogen-to-carbon ratio in compost piles. 'Brown' materials in compost, like dried leaves, straw and paper, contain carbon, while nitrogen is supplied by "green matter" like fresh or dried plant material and vegetable scraps. Blood meal also helps balance carbon content in mulch to keep nitrogen in the soil at healthy levels.
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Blood Meal to repeal Deer
Blood meal is a high nitrogen fertilizer made from dried cows' or pigs' blood. It has an earthy, slightly unpleasant smell that can deter deer. Its effectiveness depends, though, on when and how it is applied and the current environmental conditions. Regular blood meal is only effective when it is dry and must be reapplied frequently. When deer populations grow high or food is scarce, the deer are less likely to be deterred and will eat anything.