If you’ve ever tried your hand at growing heirloom tomatoes … then chances are you’ve run across Early Tomato Blight.
Early tomato blight is an infection (caused by the fungus Alternaria solani) that starts out as dark brown spots, yellowing leaves, and eventually spreads quite rapidly through the crop killing the leaves and fruits if it has a chance. The fungus spores form in hot, humid weather and then wait for a nice, cool, wet evening to start destroying the plants. We’ve definitely had more than ideal weather for blight this summer. It shows up just as the plants are starting to set fruit – and once the infection starts, it is nearly impossible to stop from spreading. If you’re growing organically and aren’t planning on dousing them with fungicide, that is.
The fungus overwinters in the soil and any garden waste that wasn’t cleaned up the previous year. We didn’t do a very good job cleaning out the garden last fall, which probably helped lead to this outbreak. I’ve also read that it can travel through the air – and I drove by a house down the road that has a bunch of tomatoes in those upside-down hanging pots – and theirs all have blight as well.
There are some blight-resistant tomato varieties, but supposedly they are lacking in flavor. Unfortunately, the heirloom tomatoes seem to be most prone to blight – and of course, every tomato plant in our garden is an heirloom variety. In this case (fortunately) it has only affected the leaves so far – the fruit seems to be untouched.
So, what to do, what to do? There are some “organic” copper and sulfur sprays that supposedly help control blight – but they still have a novel of cautionary statements on the label, and that’s not exactly my cup of tea when it comes to growing things that I’m going to put in my mouth. Since I’m not about to douse the garden in fungicide, and I’d like to at least try and get a few tomatoes this year… I pulled out my scissors and spent the better part of a day painfully removing every single infected leaf. This is very, very sad:
And now, I have tomatoes that are probably going to be sun-scalded unless they start making some new, blight-free suckers and filling in leaves. I need to pick up a few bales of straw or find someone with enough grass clippings to use as mulch, too. I guess now we just wait and see… hopefully the fruit on there now will ripen, and if the blight doesn’t come back we still have two months for them to grow.
Tips for next year: Blight can also be transmitted through seed, and so this means that I may just have to give up my 6th generation Amana Orange Tomatoes next year. Or, maybe I’ll try planting one or two from last year’s seeds in large pots on the other side of the house, just to see if they’ll stay blight-free. Fall garden cleanup, and crop rotation are definite musts. Fresh seeds and <shudder> possibly looking into some blight-resistant F1 varieties may be in order.