Confessions of an organic gardener, part I.

The Ask a Science Blogger question of the week asks if organic foods are really worth the hype. I'm afraid my answer can't fit into one blog post.

Let me start by telling you about my garden.

i-3008345f8680c3660165cbe38bfbe739-cat.jpgThis year my garden has been a home to local wildlife, but during the years that I do garden, I have a semi-organic garden.

I don't use any pesticides but I do occasionally break down and use Miracle Grow and, sometimes Epsom salts (magnesium sulfate). Overall, though I don't see any justification for using chemicals that might be harmful to fish or other animals in my garden, so I don't.

Even in the non-gardening summers, I have a compost bin that I use for grass and leaves plus two green cones that I use for composting food waste. These are sometimes a problem for me because they serve as intensive fruit fly breeding grounds in the summer months and my husband is no longer amused by finding pickled Drosophila floating about in glasses of wine.

So, you might think that I would make it a point to buy organic food, right?


I buy food based on how it looks, whether or not it's ripe, and the price. If I can buy organic food that's on sale, or I've been seduced into entering Whole Foods (it's so beautiful!), fine, but I don't make any special effort to buy organic.

Why not?

First, we should define what organic food is and what it is not.

i-d8bea5b6bdd8e18bdf50c9b695b854b4-calendula.jpgIn 2002, the U.S. Department of Agriculture, after many years of contentious debate, settled on a definition for organic foods that could be used nationally. This 554 page document, available in pdf spells out exactly which practices are consistent with the "organic" philosophy and which practices are not (1).

This document is fascinating reading and I plan to go through this document a bit more in through the coming year. Apparently, naive idea about not using pesticide is a far cry from the interesting machinations that organic farmers must go through. Some of these make sense to me, many do not.

E. coli happens
One set of rules that makes sense concerns composting. My method of composting (throw the plant material together and let it rot) is not good enough for today's organic farmers. Page 7 spells it out. Farmers must have a carbon to nitrogen ration between 25:1 and 40:1, and maintain a temperature between 131ºF and 170 ºF for 15 days.

This makes sense. Organic farmers fertilize with manure and being a microbiologist, I know manure is largely E. coli. You must get the poop hot enough to the kill the bacteria or we repeat tragic incidents like the one with Odwalla a few years back where children were infected with E. coli O157:H7 after drinking organic apple juice.

These days, they pasteurize the juice, but it doesn't hurt to kill as many bacteria as possible, before things get to that point.

I noticed though, that there isn't a requirement to actually check that the bacteria were killed.

Where's the science?

i-b126c6a5c19c6f845b3a9d0c01e4a015-forgetmenots.jpgSome you might have thought that organic farming was simply a nice friendly, non-pesticide method for growing food and animals.

And that it was based on science, right?

I'm sure there's science, this I know - because the organic web sites tell me so.

Except that I can't figure out what it is.

Stay tuned, coming up next we have: The things that cannot be organic.

1. Department of Agriculture, Agricultural Marketing Service 7 CFR Part 205 RIN" 0581-AA40 National Organic Program

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I found the points made about organic food in "Challenging Nature" by Lee M. Silver to be interesting and you seem to be echoing some of the sentiments put forth there. I look forward to your future post.

I've never been sure exactly what "organic" means and I've not seen a decent explanation given that is scientifically based (although to be fair, I haven't looked very hard). Most of what I hear about organics is based on circular explanations (it's more "natural") and a rejection of current food production methods, in some cases by throwing the baby out with the bath water.

I don't object to organic food in principle, but I fail to see how it is inherently better than properly managing what we are already doing. (And I don't blindly trumpet current practice, but I find it hard to reject it simply because it uses pesticides and additives.)

BTW, the strain of E. coli in Odwalla was O157:H7, not O1H57. Most strains are relatively benign. Just commenting for the sake of accuracy.

Geoff: thanks! The next post will be in a day or so once I've finished some projects at work.

W. Kevin: good catch! I was being lazy and typing the name from memory. I made the correction.

Good post. I've got my own thoughts on this issue, which I'll put up soon in a post now that there's someone else talking about it. A couple quick points - sometimes when I bring up some of the problems with organic agriculture, such as the fact that "no pesticides" is actually not true - there are several "organic pesticides" that they use, some kill fish for example - they get very angry and don't want to talk about it. I'd also like to note that they do not test for residues of these pesticides.
I'm seriously interested in food, more than just making good tasting food at home, and I am not satisfied with the way people talk about agriculture. There needs to be consistency in how we address these issues. A local agriculture radio show I listened to played a program about biodynamic agriculture. For those who aren't familiar, bioynamic agriculture is organic + astrology. ASTROLOGY!

I look forward to your next post on this.

For years I used Horse manure in my garden but now I am wondering just how safe that practice is and whether or not E.coli dies after a full winter? I am now 71 in age so I guess I have been lucky or my immune system has adapted or E.coli does not survive the winter.

Accidentally stumbled on this blog and thought someone could fill me in on the latest thoughts about using horse manure.


By Mike Weatherby (not verified) on 24 Oct 2008 #permalink

Mike: I think you've raised a good question, but I don't know the answer. The safety would depend on how long the manure has been composted, the temperature it reached, and the prevalence of pathogenic E. coli in horse manure.