Using bone meal for plants has been passed down for generations.
It’s made from ground up animal bones and comes in a granular or powder form.
When I did a lot of landscaping as a teenager and in my early 20s, I was using bone meal for almost all of my plantings.
But then I studied organic gardening, learned about the potential risks, and learned about a few superior products.
Mad Cow Disease (Bovine Spongiform Encephalopathy) Concerns
Starting in the mid-1980s, there has been concern as to whether using bone meal for plants might be harmful, as inhaling the dust could potentially cause variant Creutzfeldt-Jakob disease in humans.
This was mostly an issue in Europe, but people who have spent at least 3 months in places where mad cow disease has been found are not allowed to give blood in Canada or the United States.
I think there are more important things to worry about, but if you’re into the precautionary principle, you might want to use something else.
In the SOUL Organic Land Care Standard, it says using bone meal is “Allowed only if guaranteed free of specific risk materials (e.g. prions associated with Mad Cow Disease). Note: it is questionable whether sterilization disables the spread of prion diseases.” (Source)
Many certification bodies in Europe and Canada (Source) have prohibited its use due to the risk of BSE contamination. Organic bone meal is often exempt, but almost impossible to find.
It’s fairly difficult to guarantee the bone is free of prions since the nerves run through the bones, and since it’s difficult to kill them no matter how much heat and chemicals are applied, so most of us organic gardeners just don’t use it.
Many scientists claim there is little risk to humans from using bone meal for plants, but there are some who are seeing disturbing trends (here are some articles).
I won’t get into the science here and I don’t pretend to understand it all, but I’ve decided to follow the precautionary principle and stay away from using bone meal in my organic garden.
My goal is not to scare you away from using it, but just to let you know about this Mad Cow thing, and to let you know about some other great products you might want to look at instead.
What Is The Purpose Of Using Bone Meal For Plants?
Bone meal supplies phosphorus and a few other elements, but conventional and organic gardeners mainly use it for the phosphorus because it is supposedly important for root development, which is partially true.
The other thing is, how do you know you need phosphorus? Maybe your soil has enough or too much already, and adding more might just throw the nutrient balance in the soil more out of whack.
Adding concentrated minerals just for “good measure” doesn’t generally make sense, as it can set off a string of unintended reactions in the soil.
Good organic gardening practice is to add specific minerals only when you know you need them, generally based on an organic soil test, and using bone meal for plants is no different.
What Might You Use Instead?
There are 3 products I generally use when planting in my organic garden.
I talk about them in my next article: Bone Meal Alternatives
Update: Some people say I’m scare-mongering with this post. Look, I don’t know much about the research going on now – it’s just that when I was studying organic gardening, I was taught to avoid using it because my national organic standard didn’t allow it, and still doesn’t allow it. You’re certainly welcome to use it. I’m not trying to offend or scare anyone. Have a nice day!