Thursday, December 30, 2010

The Great Organic Mind Game

I've been working my way up to this post for a while now, but you know ... it's been one of those things where reality has crashed into my preconceived notions, and that's never pleasant.

When I first started growing tomatoes in South Florida, I was a nut for organic gardening. Why bother growing your own if you're not going organic, right? I initially shied away even from chemicals you're allowed to use, like copper fungicide and BT for chewing bugs. Gradually, I got more comfortable with these and eventually decided that BT was the greatest thing since sliced bread and copper was crucial.

But for those first few years, I also didn't stray too far into TomatoLand. I grew mostly disease-resistant hybrids and loved the enormous harvests of perfect red tomatoes. Slowly, though, I started adding more heirlooms into the equation and discovered I loved those too. I like funky, knobby, weirdly colored tomatoes. And I like the huge ones. You know what I want? A black tomato the size of a basketball. That's right. Bring it.

Then came this season and my run at Brandywines and Cherokee purples (in case you're wondering, that's a Brandywine up there). You don't have to look far to find people who think these are the royalty of heirloom tomatoes, and I figured, hey, I've done this a million times before, so how hard can it be? And that's when reality crashed my little party.

Turns out that my two fondest desires ran headlong into each other: growing knobby heirlooms in South Florida and being an organic maniac.

So that's been my big lesson this season so far. I'm no longer sure it's possible to grow some of the more famous heirlooms in South Florida without using more powerful chemicals to control diseases and pests. I've been asking around among the professional growers I know, and they generally agree: you want to grow heirlooms, you need to spray. Simple as that.

Now, I'm not saying there aren't exceptions. I've done hardier heirlooms before that didn't get sprayed and turned out fine. And I have a feeling this year is particularly bad for diseases for me.

I'm not saying I'll stop growing the weird heirlooms. But from now on, when I grow a tomato that isn't naturally disease resistant, I'll be following a spray schedule from the moment that plant is outside, because preventing diseases is a lot easier than treating existing diseases. This means the new Brandywines, etc., are all going to be treated from planting onward.

I don't know exactly why this feels like a let-down. I have relatives and friends who garden up north, and while they openly (and sometimes in unhealthy ways) envy our weather, they also scoff at our disease problems. These are people who can grow huge heirlooms organically and hardly worry about anything more serious than a caterpillar. They just don't get how different it is down here—that growing in the ground isn't automatically easier, that our bugs could eat their bugs for lunch (literally), and that our environment teems with bacterial and fungal diseases.

Anyway, there it is. I'm working on a spray program this season for the heirlooms, relying on research conducted at the University of Florida and North Carolina State University. I'm just about to put the second crop of heirlooms into their pots outside, so I'll keep you posted on how it's going.

And p.s., I also read that we've had the coldest December in Florida history, thanks to some annoying weather pattern known as the Arctic Oscillation. Thankfully, they say the AO, which has been in place for a year now, is beginning to break up and the "worst is over." Hats off to that.


  1. I agree with you. Organic was nice until you get hit year after year with what we finally diagnosed as grey leaf spot. Every year we would plant several different kinds of tomatoes. Perhaps a dozen or more plants, which are not cheap when you add it up, and most years get very few tomatoes.

    Finally, when we figured out what was killing the plants, we sprayed (this was 2 seasons ago) and had so many tomatoes I was giving them away by the bag.

    Last year's garden did not do too well tomato-wise due to the cold and us getting busy. This year we have not even had the time to plant our 9'x 40' garden but when we do you can bet we will spray for the grey-leaf spot fungus.

  2. Jon,

    I am growing tomatoes with my kids for the experience and also to have some great tasting tomatoes around (the family loves them). This is our first year doing it and we have learned a lot, but haven't had what I would call great success. I think part of this is poor planning and the wrong types of plants. Perhaps you can do a post on your experience with which types grow best here in Florida. We love the grape/cherry tomatoes because we get more volume. I'd be interested in knowing which ones are most disease resistant, which ones have the highest yield and which of those are the sweetest.


  3. Marcy,

    Yeah, I've been a little amazed at how quickly my plants turned around after I used chlorothalonil and maneb (following label directions, of course). This won't be a huge season, but I looking forward to some of these heirlooms.

  4. Curtis,

    That's a good idea ... because it's my experience that one of the best things we can do here is grow the right tomatoes. I'm not really experienced anywhere else, but I have a feeling it matters more for us than perhaps elsewhere.

  5. From Wikipedia:
    Long term exposure to chlorothalonil resulted in kidney damage and tumors in animal tests.

    Just sayin....

  6. Hi, JScrimsher,

    That's a good point and probably deserves a blog post of its own ...

    Quickly, I believe strongly in the principle of "least toxic option" when it comes to gardening of any kind, whether it's edibles or not. Ideally, I'd like to use nothing on my lawn and veggie garden.

    That said, I'm also not concerned about the proper usage of chlorothalonil in a home garden, strictly following label instructions. This is one of the most common fungicides in the agricultural world and, when used properly, it works.

    As far as the toxicology stuff goes, here is a link to the MSDS (material safety data sheet) for Bayer's chlorothalinol:

    These documents are mandated on all chemicals and tell how to handle it and any potential side effects. As it says, chronic exposure to high doses can cause problems in animals, and it's listed as a "possible" carcinogen in humans. BUT ... and to me, this is a big but ... animal studies are important in assessing a chemical, and they help provide a basis for the MSDS and label recommendations, but it's a mistake to translate animal studies to the effects of a chemical in humans (this is also VERY true in pharmaceutical and nutraceutical research). As awful as it is (and I've got plenty of vegan friends who find this morally reprehensible), in an animal study, they give the subject animals extraordinarily high doses of the chemical in question for a very long time, then destroy the animal and do an autopsy. These are hardly the conditions any human would use this chemical under.

    I know this is a highly charged subject—and I respect that many people feel very strongly about the use of agricultural chemicals that might have environmental and health side effects, especially if used incorrectly. I think it's something that every gardener who grows food will have to confront and make a decision, based on the information that's available to us. But I also think there's a fair amount of misinformation that floats around out there. Last year was valuable to me because I resisted the use of a stronger fungicide for a long time, and ultimately, I think the only reason I ended up harvesting tomatoes was because I did use a stronger fungicide than I normally use. Do I feel like I endangered my family with this? No, not really. I strictly followed the label directions for application and harvest, I washed the vegetables carefully, and I discontinued use as soon as the problem was in hand. But will I use it again this year? Honestly? Not unless I absolutely have to ...

  7. Good Afternoon,

    Can you tell me which seeds would have the best success in south florida, specifically the west coast?

    I am looking for tomatoes, melons, peppers, and anything else you would recommend growing organically in my area(Naples FL)

    1. Which organic watermelon strains have the most resistance to anthracnose-race 1 and fusarium wilt?

    2. WHich organic tomato strains have the most resistance to Verticillium wilt (race 1), Fusarium wilt (race 1 and 2), and gray leaf spot?

    3.Which organic bell pepper strains have the most resistance to Xcv 1, 2, 3, 4, 5 – Bacterial spot, Tobacco Etch/mosaic, and Pepper mottle?

    I know I have a lot of very specific questions, however any guidance you can give me would be much appreciated. I am trying to start an organic farm and am using this year as a test year for organic vegetables. Thank you very much for your time. Please answer at your earliest convenience.

  8. Hey, Anon ... in general, seeds themselves are not organic. At places like TomatoFest, a highly respected website, they sell seeds that came from organically grown tomatoes, so you might consider those. But for the most part, seeds are just seeds. It's how you grow them that will yield organic tomatoes or not. If you follow organic growing practices, you can have organically grown hybrids, while if you use non-organic chemicals, you can have non-organic heirlooms and vice versa.

    So the question probably isn't "which organic tomato strains" have resistance ... it's "which heirloom or heritage tomatoes" have the best resistance. And really, that kind of depends. I had great luck with the green zebras, Cherokee purples, Kellogg's breakfast, and giant Belgians. The Brandywines had more mold susceptibility. I've done well with a Russian yellow tomato called an Azoychka. I also do follow a preventive spraying program with copper fungicide, which helps cut down on the wilts.

    In general, I've found that it's MUCH easier to do an organic grow in the winter growing season and to use hybrids that have been bred for greater disease resistance. Heirlooms are generally not bred for disease resistance, and usually have a harder time dealing with our intense humidity and heat and bugs than hardier hybrids. So, if I was pursuing commercial production of organic tomatoes, I would get a good hybrid with proven disease resistance and go from there. There are many varieties.

    Lastly, I don't really grow watermelon or bell peppers, so I'm afraid I can't be much help there.