Decision Time

This is not a post I wanted to write.

I've been growing tomatoes for a long time, but this year seems to be the year when Bad Things Will Happen. Despite treating with copper fungicide, the septoria leaf spot I wrote about last week has continued to spread through the tomatoes—even tomatoes that are more than 50 feet apart are all suffering from it.

At first, I couldn't figure out why this year would be so much worse than any other. I've had leaf spot every year and been able to control it with copper fungicide spray (organic), good tomato hygiene and leaf removal. For a while, I thought it might be the mix of heirloom and heritage tomatoes I'm growing, but that argument never really made sense. I've grown heirlooms and heritage tomatoes before with no problem.

The best explanation I can come up with is construction. ("Huh?" you say. "Construction?") Yeah, construction. My neighborhood is the midst of a pretty massive infrastructure project. The roads are all torn up and our cars are continually covered with dust. The pool filter has to be backflushed almost every week. So obviously, there's a lot of particulate matter in the air this year—and fungal diseases live in the ground. My best theory now is that my plants are being coated with airborne fungal spores stirred up from road construction.

Anyway, it doesn't really matter why, because I have to figure out what to do. The copper spray is not working—the disease has continued to spread relentlessly. Here is the breakdown:

• Brandywine: Lightly affected
• Victoria Supreme paste tomatoes: Unaffected (this one, btw, is VFFNA)
• Yellow pear: Severely affected
• Heinz tomatoes: Severely affected
• Cherokee Purple: Moderately affected

So ... my decision basically is this: do I switch to a stronger, commercial fungicide? The two best fungicides to control septoria leaf spot are chlorothalonil (sold as Daconil) and mancozeb (sold as Bonide Mancozeb). Of these, Daconil is easier to get—I believe they stock it at most large garden centers. As for efficacy, I looked for studies and didn't really see a consensus. According to North Carolina State University, mancozeb provides superior control for septoria, while some state ag departments I looked at recommended chlorothalonil.

Unfortunately, with the way this is spreading, I think my choice is pretty clear: treat with Daconil (primarily for convenience) or dramatically lower my expectations for this season's crop.

Bummer.

Going Ninja

The last few days have been a frenzy of black spots on my young tomato plants. But before I get to methods to control these, it's worth trying to figure out what they are exactly.

There are a number of organisms that can cause black spotting on tomato leaves, especially when the plant first sets fruit. They include Septoria leaf spot (a fungus), bacterial spot (Xanthomonas campestris), bacterial speck, and few others. In general, these are controllable, while some of the more terrifying wilts and blights are killers.

Most of these conditions are caused by the rapid spread of an infectious organism among your tomato plants. Just like in people, these little buggers like warm, wet conditions, so the early part of the season is especially dangerous for us as it's typically still hot and muggy—perfect weather for a bacterial or fungal infection.

In this case, I'm guessing I have Septoria leaf spot, which is characterized by wet lesions on the underside of leaves that develop in black spots with gray centers. Septoria is a fungal infection caused by warm, wet conditions. It is pretty much always present in South Florida, so ... you know, hard to avoid.

I always hate seeing this happen, even though it happens every year.

To control these kinds of diseases, start with prevention. Plant tomatoes in fresh soil, leave them far enough apart that the organism can't easily jump from plant to plant, and never water from overhead.

After you get it, this is what I do: apply a copper fungicide spray according to the label directions (weekly) and religiously remove any affected leaves. Copper fungicide is rated for organic growth, so you can use it on your plants and still have organic tomatoes. So obviously, it's not the strongest fungicide on the market—if you really want to go ninja on fungal diseases, you can switch to a much stronger product such as maneb or mancozeb. These are commercial-strength products.

Personally, I don't use 'em. I cut away leaves, slow it down with the copper spray, and hope the temperatures and humidity break in time for the plant to outgrow the infection. This has worked for me well enough, and I can avoid the stronger fungicides.

As a side note, I'm still really looking forward to the yellow pear tomatoes. EVERYONE loves them. But, man, me and yellow tomatoes have a rocky relationship, and this year is no different. These things are driving me crazy—leaf roll, fungal diseases, and of course, the tomato leaf curl virus. If anyone out there has experience successfully growing yellow tomatoes in South Florida, I'd love to pick your brain ...

Good Morning, 'Maters.

I like these mornings during vegetable season ... I get up when it's dark, get the kids off to school, and spend a few minutes with the tomatoes before going to work.

It's nice.

I know people have very strong opinions about organic versus non-organic, and what kind of growing medium is best, and even what variety of tomato is best, but I'm not really a "point of view" gardener. I'm not really trying to impose my belief system on the garden. I think I've tried almost everything, and you know what? I've grown good tomatoes almost every way. I've harvested excellent, tasty tomatoes with regular Miracle-Gro tomato fertilizer and common bagged soil—just like I've harvested awesome tomatoes with high-end micronutrient foliar sprays, exotic organic fertilizer blends, homemade compost, and custom soil mixes. I've eaten good tomatoes from the ground, containers and Earthboxes.

I would never want to make it seem harder than it is. If anyone was to ask me, "What's the best way to grow vegetables?" I'd say: every day, bit by bit.

No matter what other choices you make, I think if you're willing to spend a little time every morning with your plants (or at least every other morning), everything will be fine. Give them water on a consistent schedule (I actually water every day), feed small amounts of food consistently, and mostly, pay attention. Your plants will do a remarkable job of telling you what's going on. Do you see spots on leaves? Yellow streaking? Are there holes chewed in the leaves? Are they surrounded by flies? Are the blossoms dropping off or setting fruit? Is the fruit developing normally?

The only way to really find out what's going on is just to keep an eye open for it. And chances are, it will be easier to deal with than you think.

So these are easy, rhythmic days. Watering, watching, feeding weekly, tying up the vines as they grow, and plucking off suckers. Really, there are much worse ways to start a day.