Bone meal does not help your plants. This is a myth that is found so extensively you would think it had been propagated from seed. From Linda Chalker-Scott of Washington State University
- Bone meal supplies high levels of phosphorus and calcium, elements that are rarely limiting in non-agricultural soils.
- Phosphorus, from
bone meal or other sources, does not “stimulate” plant growth; it is only a mineral, not a plant growth regulator.
- High levels of
phosphorus, from bone meal or other sources, will inhibit growth of mycorrhizal fungi.
- Without mycorrhizal partners, plants must put
additional resources into root growth at the expense of other tissues and functions.
I also highly recommend her book about gardening myths which I read and shows how you can achieve the same or better gardening results with less work.
Edit: both blood and bone meal are byproducts from the meat packing industry. Blood meal is a good source of nitrogen. They are sometimes packaged together as blood and bone meal. The key differences are that:
- nitrogen is mobile and not tightly bound in the soil so it can be used by roots quickly
- some plants are heavy nitrogen users like corn or many green vegetables so it is a limiting factor
Edit @Ed Staub There is a difference between phosphorous must be present for root growth and "Bone meal helps stimulate strong root growth" or this site. In regards to mycorrhizal fungi "Approximately 90% of all vascular land plants live in some association with mycorrhizal fungi". That does not endorse selling MF supplements it just underlines that if you inhibit the growth of a plant's symbiotes then mineral uptake is decreased until more roots are grown. I would be very interested in any research that substantiates the claims that are made for bone meal.