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Mad Cow Disease, Its Close Relative’s Affect On Humans, and Simple Old Bone Meal; Plus Mosaïculture
by Art Drysdale
by Art Drysdale


Art Drysdale, a life-long resident of Toronto and a horticulturist well known all across Canada, is now a resident of Parksville, British Columbia on Vancouver Island, just north of Nanaimo. He has reno-vated an old home and has a new garden there. His radio gardening vignettes are heard in south-western Ontario over radio station Easy 101 FM out of Tillsonburg at 2 PM weekdays.

Art also has his own website at

March 25, 2001


alliums.jpg (212238 bytes)
Spring flowering bulbs such as my tulips and alliums shown here are an example of the plants that many so-called experts recommend fertilizing with bone meal. Wrong! Instead, use a fertilizer such as Bulb Booster at the time you plant the bulbs. 
Author photo.

Just about six weeks ago I wrote a fairly detailed treatise on why I have been recommending AGAINST the use of bone meal for any and all garden plants for the past 40 years. It was entitled “Spring is coming, bone meal advocates will be out in full force--but don’t be fooled!” It was my “Last Word” editorial for the March issue of Plant & Garden magazine. If you didn’t see it, and don’t subscribe to the magazine (you really should subscribe--it’s Canada’s practical gardening magazine, and the oldest national gardening magazine in this country), you may read it as one of my ‘Commentaries’ on my website:
Since that time mad cow disease, or bovine spongiform encephalopathy (BSE), has hit Britain and the European community and has forced farmers there to destroy thousands of cattle and sheep. Despite all the efforts to control the disease, and denials that it is harmful to humans, the CBS programme 60 Minutes II, last Monday night ran a detailed item about a number of people in Britain who had contracted the human form of the disease, variant Creutzfeld-Jakob Disease (CJD). All of them have died. 
Not a great deal is known about this disease but it is known that it is spread by “prions” from the brains of animals. Prions are non-living infectious proteins that cannot be destroyed by sterilization or burning. It is also known that they can last in soils for years and years. There is certainly no clear indication of how any of the British casualties contacted this human form. It certainly could have been through eating meat from infected animals. Another way could be by working in soil contaminated with the disease, possibly even through the use of bone meal, made from animals that were unknowingly infected. Bone meal is often a dusty product, hence even breathing that dust, or absorbing it through cuts or bruises could well be dangerous.
Here in Canada, there are a number of different brands of bone meal available. Basically it is still cattle bones that are ground up and then steamed that make up the bone meal, but as mentioned in my earlier piece, it is not really a complete fertilizer because virtually all of the nitrogen is steamed out for other uses. Those who sell this bone meal tell me they are extremely scrupulous in purchasing only cattle bones from Canada, and to exclude any bones from imported cattle. I am also told that most of the bone meal produced in eastern Canada is steamed, but that some produced in western Canada may well be “chipped bone meal” that is actually micro waved to purify it. Such bone meal is usually identified as made from “chipped bones.” In addition to being a completely different product, the production process being less expensive means that this chipped bone meal is often cheaper than the older, conventional steamed bone meal. Therein lies the need for even greater caution now that CJD has been found to be a concern. There seems little doubt that the more expensive steaming process is superior to micro waving, but then we already know that the “prions” that cause CJD are not destroyed by either process.
The leading producer of bone meal in Canada is the Nu-Gro Corporation, based in Brantford, Ontario. With recent acquisitions, Nu-Gro now offers their steamed bone meal to you the gardening consumer in four distinct lines: Green Earth, CIL, SoGreen, and Vigoro. To help alleviate the problem of users inhaling dust from these products, all of them are now granulated to make use and handling easy.
Having said all that, with what has happened in Britain and Europe, particularly the occurrence of CJD, and having at hand all of the negatives about the product, I have to ask, why are gardeners using it at all? 
There are far superior products out there for all purposes. One traditional use for bone meal, as recommended by so-called “natural gardeners”, is in fertilizing spring-flowering Dutch bulbs. Now, as mentioned in the March 2001 Plant & Garden “Last Word” item, horticultural scientist and late friend, Dr. R. Milton Carleton confirmed decades ago: “The bones are steamed to extract gelatine and other by-products. This removes most of the amino acids, a valuable source of nitrogen. Further processing removes all but about one-half percent of the nitrogen. What is left is a substance considerably less desirable as fertilizer material.” 
While the phosphorus in bone meal may be seen to be of value to the bulbs, it is not when it is exclusive of nitrogen. The bulbs need nitrogen in order to produce foliage on which the flower buds are developed. Far better to use a product such as Bulb Booster, developed especially to feed bulbs, and to be applied at the same time the bulbs are planted, in the fall.
Whatever you do, follow my four-decade-old advice--skip the bone meal!
Just enough room to mention that the spectacular one-time-only Mosaïculture exhibit that was not only a stunning floral surprise in Montréal last year, but also the first of its kind in North America, will be back this year! The theme for the 2001 season is to be “The Magicians’ Garden”. Site will be the same, at the Old Port of Montreal, from June 22 to October 8. If you didn’t see this and you’re going to be anywhere near Montréal this summer or early fall, do put it on your calendar as a must-see. I will be doing that. I missed it last year due to a whole raft of appointments. On my radio programme I did have a live-from-the-scene report from friend Larry Sherk, chief horticulturist for Sheridan Nurseries, but this year I intend to see it for myself. Admission will be $10 per adult with special prices for families and groups. For group information call SPEC at 1-888-868-9999.

Art C. Drysdale, 6 Nesbitt Drive, Toronto, Ontario M4W 2G3

Art Drysdale is horticultural editor of Canada's oldest and fastest growing national gardening magazine, Plant & Garden. He is heard Saturdays from 8 to 10 AM, with a live radio broadcast on Toronto's powerful and clear, AM740 CHWO Primetime Radio.


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