Its more common name is Late Blight. This week last year, the leaves of my tomato plants started showing black lesions. I tried to fight the fungus by spraying a copper solution, clipping off diseased branches, and in many cases pulling up entire plants. We picked a lot of green tomatoes last year.
This year, I used red plastic mulch on two tomato beds and can report that it really works. The plants growing over it are significantly larger and more fruitful than the others. And the tomatoes planted around buckets of compost with holes in the bottom, plus the red mulch, are doing the best of all (as shown in photo).
The tomatoes have loved the abundant rain of the past eight weeks, and haven’t minded the cooler-than-normal temperatures as much as the peppers and eggplants.
I have six Big Boy tomato plants that I bought at a nursery and four Cosmonaut Volkovs that I grew from seed (the Volkovs adapt well to my cylindrical cages because they don’t branch out). Most of these have the red plastic mulch. I have four Honeydrop cherry tomato plants, two of which are doing well growing in buckets of compost. The three Bobcats are poking along, but my one paste-type plant is thriving.
As a hedge against the Black Death, I’m growing one plant each of two resistant varieties called Mountain Merit and Defiant. (I love the names they give to tomatoes.) I’m also growing one mystery tomato plant (it looks like a Brandywine). That makes 21 plants in all.
Because of Late Blight, we preserved only 25 quarts of tomatoes in glass jars last year, and ran out several weeks ago. Because tomatoes have high acid levels, they may leach out more of the hazardous chemicals put in can liners than other foods do. I’m growing plum tomatoes to try to avoid using cans of paste.
To fight the blight, I started spraying with a copper product called Soap Shield on July 6 and have sprayed twice more since then. It’s approved for organic gardens, but I still cover my skin and put a handkerchief over my mouth and nose while spraying. I try to spray before humid or rainy periods, because those are the conditions the blight favors.
Does it work? I don’t know. Yesterday a tomato grower told me she’s spraying hydrogen peroxide to avoid the blight.
So I’m just crossing my fingers and hoping for an abundant harvest!
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