No, watering plants with blood from the butcher is a bad idea. Raw blood carries germs, draws pests, and rots in soil. The safer pick is dried blood meal mixed with water.
I first heard this trick from an old uncle who said his grandfather poured pig blood on the rose beds. The flowers grew well, but the smell drew in stray dogs and rats from blocks away.
When I tried a small test with raw blood on a back corner of my garden, the same thing happened to me. Within two days a fox dug up the whole row in search of a meal.
Raw blood breaks down without air in the soil. That kind of rot makes harsh gases and can pull germs into your plants.
Heat-treated blood meal is safe because the factory cooks the blood at high heat. The USDA sets strict rules under 9 CFR 95.25 to kill any germs in the powder before it ships.
Raw Blood Risks
- Germ load: Raw blood from a butcher shop carries bacteria like E. coli and salmonella that can spread to crops.
- Pest draw: The smell pulls in dogs, rats, raccoons, and flies, all of which dig up beds to find the source.
- Bad rot: Without air, blood breaks down into harsh gases that can hurt root systems in the soil below.
Dried Blood Meal Benefits
- Heat-treated: Factories cook blood at high heat to meet USDA 9 CFR 95.25 rules and kill any germs in the powder.
- Stable feed: The dry form lasts for years in storage with no rot or smell when kept in a sealed bin.
- Easy to mix: A scoop dissolves in warm water to make a clean liquid feed for use as a soil drench.
Research-Backed Method
- Chan et al. (2007): Showed that dried blood meal mixed in water at 80°C (176°F) breaks down into a clean liquid feed.
- Nutrient profile: The mix carries peptides, amino acids, and ammonia, all of which feed plants fast through roots.
- Safer for crops: No germs, no smell, and no pest draw, since the heat step kills off all the bad stuff in the powder.
Liquid blood meal is the safe way to get the same fast nitrogen boost without the mess. You skip the bug draw, the smell, and the germ risk all at once with this clean method.
Blood fertilizer safety comes down to one rule. Always use dried, processed blood meal from a trusted brand, never raw blood from a kitchen or butcher shop.
For a DIY nitrogen fertilizer, the recipe is easy. Mix 1 tablespoon (15 ml) of blood meal into 1 gallon (3.8 liters) of warm water and stir well until the powder breaks up.
Let the mix sit for 24 hours so the powder fully breaks down. Strain it through a fine mesh, then pour the liquid as a soil drench around the base of hungry plants.
I use this drench on my tomato beds in June when the plants start to flower. The leaves stay dark green and the fruit set picks up within a week of the first dose.
Apply the liquid feed once every 2 to 3 weeks during the growing season. Skip the drench in fall and winter when plants slow down and do not need a heavy nitrogen push.
Read the full article: Blood Meal Fertilizer: NPK and Best Crops
