A Bill Finch Plain Gardening Column from July 2012 - reprinted with permission
They call it bacterial wilt, but you know it as the heartbreak disease.
It’s a killer for any of us who love tomatoes, because it seems to focus almost all of its damage on tomatoes, and always strikes when your tomatoes are at their peak, when your tomatoes are the picture of tomato health, so full of tomatoes that you’ve got sugar plum fairies dancing around in your head.
The next day, the leaves are flagging for no apparent reason, and you water and scratch your head. Two days later, the plant is dead. Boom. Almost overnight. And you get this horrible feeling in the pit of your stomach like your girlfriend just ran off with the mailman.
That, simply, is how you know you’ve got bacterial wilt. Nothing else will wreck your tomatoes in such a distinctive and immediate way. No other tomato disease will leave you feeling so hollow and useless inside.
Bacterial wilt: later stages
And of course, what can you do once you’ve got it? Even if there were such a thing as emergency rooms and intensive care units for plants (there are none, I’ll remind you), what good would it do? Because by the time you recognize your plants are suffering from bacterial wilt, the disease has already progressed to the point that the entire plant is just hours away from total collapse.
Let me wring your broken heart one more time by letting you know that bacterial wilt is distressingly common along the Gulf Coast. I don’t know of any gardener who grows tomatoes frequently who hasn’t suffered from it. Shoot, we lost some of our tomatoes at Mobile Botanical Gardens to the disease. And some gardeners have been hit by it so many years in a row, they’ve simply abandoned growing tomatoes in their yards.
But wait. There’s no need for you to abandon tomato growing. If you understand the conditions that promote the development of the disease, you may be able to avoid it entirely.
The bacteria that promote bacterial wilt are likely already in your soil. But they don’t seem to proliferate and bother your tomatoes except when the soils are sopping wet with moisture for long periods, and when the roots of your plant have been repeatedly stabbed and chewed on by the minute soil creatures known as nematodes. These nematodes leave holes in the roots that give easy access to bacteria.
I’ve been able to avoid bacterial wilt almost entirely in my home garden by creating a fresh, 6-inch layer of topsoil each year in the areas where I grow my tomatoes. This layer of new “SuperSoil” — created, very simply, when a pile of leaves broke down into topsoil over the winter — provides excellent drainage that discourages the kind of wet soils that bacterial wilt thrives in. This fresh layer of soil is also relatively free of the wilt bacteria. And because nematodes travel into new soil very slowly and don’t do well in soils high in organic matter, there’s very little nematode damage to the roots of my tomatoes, and thus very few entry points for the bacteria.
I supplement this technique by rotating the tomatoes to a new part of the garden each year. Creating a fresh layer of topsoil may be almost as good as rotating, but with a disease like bacterial wilt, you may not want to take any chances.
You can try some of the new bacterial-wilt resistant tomato varieties, like the Hawaiian tomato called Kewalo. There aren’t many of these varieties, I should warn you, and some have complained about a lack of taste.
And finally, you can, as some gardeners do, resort to growing your tomatoes in containers in sterilized commercial soils. You’ll certainly avoid bacterial wilt that way, but you may encounter a few other difficulties along the way.
Bill Finch - Plain Gardening July 2012
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