For many gardeners, including myself, it's been a tough year for tomatoes.
A cool, wet spring followed by heat and humidity was the perfect storm for fungal diseases. Tomatoes are prone to fungal issues.
The most common is early blight, which is problematic, but usually not fatal. It begins at the bottom of the plant, turning leaves yellow and brown and then works its way upwards. Usually during a "normal" season the plants will rebound when things dry out and warm up. When gardeners remove the infected foliage, the plants produce just fine.
While working in the garden yesterday I noticed discolored tomatoes on one plant, after closer inspection I determined the disease to me late blight. It's the worst thing which can happen to a tomato plant. The disease is always fatal and has probably already infected every plant in the garden.
Late blight is airborne, creating millions of spores and spreading them as far as they can float. The good news is the season is almost over. The bad news is I might not be able to pick the last tomatoes and ripen them indoors as I usually do.
In the case of late blight, there's nothing a gardener can do as far as the soil is concerned. One there's a freeze, the spores are killed. Next season we're not any more prone to the disease because the plant were infected this year. The most important control is to remove any plant infected with late blight. They can't be composted and need to be either bagged, buried or burned. Even though a freeze will kill the spores above ground, the disease can survive underground.
We had a season a few years ago where late blight ran rampant mid-season and many gardeners didn't pick tomatoes that summer.
There are preventative measures which can be taken during the season though to combat late blight. The number one thing I should have done was treat the plants with an organic fungicide like Serenade. This is only effective in the case of late blight by treating BEFORE seeing signs of damage.
I've had late blight before at the end of the season and it's a little disappointing, but this is part of gardening.
I'm going to remove the plant and cross my fingers that my other plants will produce before frost and not show signs of late blight.