Over the last week or so I’ve read two books by Jeff Gillman, a professor in the department of horticultural science at the University of Minnesota. The books were The Truth About Organic Gardening: Benefits, Drawbacks, and the Bottom Line, and The Truth About Garden Remedies: What Works, What Doesn’t & Why, both from Timber Press.
What I found refreshing about these books was the reasoned approach Gillman took. He approached his subject scientifically and provided either reports from scientific studies or conducted studies himself and reported the results. This is a more rational treatment of these subjects than I've seen anywhere else.
The most important myth he investigated and shattered was that organic pesticides are completely safe and/or are always safer than synthetic pesticides (i.e. the "if it's organic it's natural so it must be safe" school of thought.) We're reminded that many natural things are dangerous. Cyanide for example.
Gillman makes it clear that he is not in favour of using any kind of pesticide (synthetic or organic) willy-nilly, and indeed infers that using no pesticide would be the best case. But he recognizes that large scale food production (we’re talking farmers, not residential gardeners with a sandbox sized plot.), both conventional and organic, does require the control of pests and diseases in some manner.
In The Truth About Organic Gardening Gillman walks the reader through organic and synthetic/conventional approaches, products, and practices, and clearly summarizes the benefits, drawbacks, and bottom line for each. It’s well worth a read, although one of his conclusions made me wonder whether it we’d all have to resort to growing our own food:
“Taken as a whole, the available information points to the inescapable conclusion that it’s highly likely that organic produce, and especially organic produce from plant species that need to be sprayed a lot in conventional production systems, contains residues of organic pesticides that may be just as harmful as their synthetic cousins, or, as in the case of some toxins like rotenone, perhaps even more so. Once we realize that pesticide residues of one sort or another are probably on at least some of our food, the question then becomes how dangerous these residues actually are to us—and the answer, unfortunately, is that nobody knows." (p. 183)
This book equipped me with the knowledge to make more informed choices if I decide I need to use a pesticide of some form in my garden--I can now weigh whether an organic or synthetic product will do the least amount of harm to people and the environment. My final tidbit from this book is watch out for rotenone—it’s organic and widely available but Gillman’s bottom line assessment was “Why would any sane person use this pesticide?” After reading this book, that's enough to make me run the other way!
In The Truth About Garden Remedies Gillman takes on everyone’s favourite home made and commercial garden remedies: flame throwers to control weeds (can work, but you’ve really got to be careful), egg shells to control slugs (No. This surprised the author so much he repeated his test a couple times but reached the same conclusion,) baking soda spray for fungus (spraying water was just as effective), etc. This is a handy book for any avid gardener to have around. I think I’ll be buying a couple copies as gifts.