If you don't need it, don't use it. Is your soil P deficient? Is it acidic?

Most garden soils are not P deficient but always good to test before applying anything (other than N which always needs replacement/supplementation). And studies have shown that the P obtained from bone meal needs acidic soils to become available to plants.

The need for adding these amendments/fertilizers is often overstated. Horticulturists have concluded that:

• 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.

To read more on what benefits bone meal may have as well as the risks involved with applying when not needed, look here The Myth of Beneficial Bonemeal

Thank you, gardengal! Actually, I believe I have the conditions that would require it -- probably why the PO had it in the first place! I'll read up on it at your link...

If I had that bag, I'd sprinkle some on all the growing daffodils and tulips. I usually do this with a balanced organic fertilizer before a spring rain, but if I had an old bag of bone meal it would do just fine.

I was wondering if it could be sprinkled on the soil over my spring bulbs -- good idea to do it before a rain! Thanks.