first job when I graduated from The Niagara Parks Commission Botanical
Garden and School of Horticulture, was with the Shur-Gain Division of
Canada Packers, where I was in charge of, among other things, writing
directions for use of new consumer fertilizer products, formulating and
conducting tests on experimental products (such as the first weed and feed
product in Canada), and generally informing the trade and the public of
advances in plant nutrition. I had just come from a school where we were
taught in great detail about fertilizers--particularly those that were “natural”.
I well recall the late ‘Bert’ Henning, our endeared school
superintendent, preaching the use of some of the oddest concoctions as
plant foods. These included seaweed (still available) cottonseed mash, and
of course blood meal and bone meal.
I arrived in Toronto’s packinghouse district with all this knowledge,
only to find that the country’s leading producer of bone meal--Swift
Canadian--itself admitted that virtually all of the bone meal from all of
the packinghouses was even then (1961) going into the production of the
much higher-priced feeding bone meal. (Some time earlier the major
packinghouses had agreed that on certain
not-large-volume-not-very-profitable products, one packinghouse in an area
would process the entire amount of that product, and Swift Canadian was
the designated processor of bone meal.)
additional problem was that any bone left over from feeding bone meal
production (basically the very poor quality bone; all the best quality
went for the feeding bone meal) was being subjected to greatly increased
steaming techniques to extract gelatine and other saleable by-products. In
a sentence, the bone meal being offered for sale, even 40 years ago, was
definitely inferior to using the ever-so-much cheaper super phosphate
0-20-0 for the application of phosphorus to encourage root growth as well
as flower and seed production.
almost two decades from that point on I had been preaching the exclusion
of bone meal from gardens, not just because it was overly expensive, but
also because it in some cases, could be a negative in garden soils.
an old friend came to the rescue--Dr. R. Milton Carleton, horticultural
scientist with the Vaughan Seed Company in Chicago (see info on “Milt”
in my September, 2000 Commentary), wrote a piece in News and Views,
published by the American Horticultural Society. It was reprinted in the
prestigious Brooklyn Botanic Garden Record, Vol. 37 No. 4, published in
the winter of 1981-82. In his piece Milt reiterated much of what I had
been telling my audiences through the 60s and 70s, as garnered first-hand
from my involvement with the packinghouse industry in this country. Here
are excerpts from Milt’s item, still valuable comments today.
the value of bone meal as a fertilizer and someone is certain to rise and
say, ‘If you’re so smart, why is it that our grandfathers have used
bone meal for years and have been satisfied with the results?’
accusation has a very simple answer. Comparing the bone meal of
grandfather’s day and the commercial product sold today is like
comparing a dish of old-fashioned oatmeal with a serving of devitalized,
dehydrated corn flakes. They are not identical.
the potting shed on big estates in England, or perhaps the hen house on
humbler properties, there stood a bone grinding mill operated by a huge
wheel. It was used to crush bones from the kitchen and was used either as
a poultry feed or a garden fertilizer. Into this mill went fresh bone,
perhaps from a rare roast with bits of meat still clinging to it. The
marrow contained blood and also some phosphorus still in transit in the
animal when slaughtered and not deposited as insoluble tricalcium
phosphate, the basic building block of skeletal matter. The ground bone
contained as much as six percent nitrogen.
this compare with the dry, white bone meal of commerce? Today, bones are a
valuable source of packinghouse by-products; elements needed by plants but
worth far more in other forms. 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.
I had an occasion to examine a lawn on which the owner had faithfully
applied fifty pounds of bone meal every spring for 20 years. It was pale
in colour and growing poorly. A divot removed from the turf showed a
distinct white line, nearly half an inch deep, just below the surface.
Among other adverse effects, this layer of bone meal had locked up
practically every trace of iron, robbing the grass plants of a basic
nutrient needed for chlorophyll formation. It is obvious that today’s
bone meal is not what it used to be. In fact, it may sometimes do more
harm than good when added to the soil.”
One final comment about blood meal: I also remember the guys at Canada Packers working in blood meal processing at the plant. They could only work in ten-minute shifts or they would pass out from the strong stench. Now, blood meal has been considerably deodorized and it is still the best fertilizer for the likes of arborvitae and cedars. But do keep in mind it can create a smell not all that desirable!