Blood meal is a high-nitrogen organic fertilizer made from dried, powdered animal blood, typically sourced from cattle or hogs as a byproduct of the meat industry. Gardeners frequently use this fine, dark powder to provide a rapid, non-synthetic nitrogen boost to plants. However, the organic nature and origin of blood meal create a common concern regarding its potential to attract animals to garden beds.
The Composition That Attracts
The attraction animals feel toward blood meal is purely chemical, driven by its high nutritional value. Blood meal contains a massive concentration of protein, often ranging between 80 to 90%, making it a highly desirable food signal for many species. The scent that results from this protein is easily perceived by animals with sensitive olfactory systems, acting as a beacon for an easy calorie source. The metallic odor associated with blood is primarily caused by a volatile chemical compound called trans-4,5-epoxy-(E)-2-decenal. This molecule is detected by predators as a sign of a readily available, high-protein meal.
Animals Most Drawn to Blood Meal
The animals most significantly drawn to blood meal are those whose diets naturally include meat or scavenging, specifically domestic pets and various omnivores. Dogs are highly susceptible to the scent and will often dig aggressively in garden beds to reach the source of the dried blood. Ingesting large quantities can lead to severe gastric distress, vomiting, and diarrhea due to the concentrated protein and iron content.
Scavenging omnivores, such as raccoons, opossums, and skunks, also find the strong scent appealing as they search for calorie-dense food sources. These animals are prone to causing extensive damage by digging up plants and disrupting topsoil. A conflicting response exists among herbivores like deer and rabbits, as the scent of blood can sometimes signal a predator or danger, leading to a deterrent effect. However, this repellent property is unreliable and often temporary.
Application Methods to Reduce Attraction
Gardeners can significantly reduce animal attraction by focusing on odor elimination and thorough incorporation. The most effective method is to completely mix the powder into the soil rather than broadcasting it on the surface. This ensures the nitrogen is deep enough to be utilized by plant roots and less accessible to foraging animals.
Immediately after working the blood meal into the soil, water the area thoroughly. This saturates the product, helping to dissolve the finer particles and integrate the material into the soil matrix, which minimizes the surface scent. Frequent, lighter applications are also preferable over a single, heavy broadcast to limit the total amount of available surface odor at any given time.
Another practical solution is to strategically mask the blood meal’s scent by pairing it with other strong-smelling substances. Applying deterrents like cayenne pepper, strong essential oils, or wood ash around the treated area can help confuse the animals’ olfactory senses.