Sorry, I didn't put this in my earlier post, but I have already looked through other postings with numerous search keywords, but I have yet to find a picture of the black spots without yellow halo's or anything that looks like what my little plants have. Thanks!

Chickenlittle, I have the same spots on my tomatoes ... just started happening and I also have no idea what it is. I hope someone can help!!! I have it on yellow pear tomatoes and my Cherry tomatoes.

I'm having a similar/same? problem along the edges of my leaves. My pictures look like this:

And strangely... It's my Sweet 100 and yellow pear tomato too. I got mine as transpalnts from Lowe's. And before this new thing it was a leafminer battle.

I really hope someone helps us figure it out.

V.

I realize this thread is 9 years old, but has anyone figured out and answer in those years? :-) I have the same problem on some of my tomatoes. I dusted them with a copper fungicide just because I didn't know what else to do.

Are you having the leaf margin problem, or the little spots without haloes problem?

Because I am dealing with the same issue, after researching for a solution, nearly every pro-gardener recommends spraying your plant with Neem oil, apparently this is the most organic and effective method. However, I'm curious, because any water that get's onto my tomato leaves, so far, turns into a transparent spot.

Neem is not ideal for fungus, although it can help. It can also harm beneficial insects, though, as it has broad anti-pest activity.

The picture with the blackened edges is more likely to be burn from too much fertilizer.

The spots could be bacterial speck, bacterial spot, or septoria. I've had those spots appear, also without haloes at first. The affected leaves eventually turn yellow and die. Bacterial spot and speck will affect fruit eventually (though it's not guaranteed) and septoria will not. Bacterial speck is limited to tomatoes, but bacterial spot and septoria can affect other plants, especially peppers. Bacterial spot likes hot temps, bacterial speck prefers cooler temps, and septoria can be active in cool or warm temps. This may help with diagnosis, or it may not. Short of lab testing, it's hard to tell them apart unless fruit symptoms arise. Fruit affected by the bacterial diseases is still edible; bacterial speck lesions are only skin-deep and can be scraped off with a fingernail, although spot lesions can go deeper. They won't hurt you if you eat them and are more of a problem for market growers, who can't sell visibly diseased fruit, but some people advise against using affected fruit for canning. Some people say not to save or share seed from diseased plants. Others say that fermentation of seeds or other treatments (hot water, bleach, H2O2, etc.) will prevent disease spread.

Spraying fungicide that targets all 3 possibilities and diligently pruning off any afflicted foliage can slow down all 3 so that plants will still produce a decent harvest. There is no real cure once you see it, though, so a preventative spraying regimen is a good idea. There are many options as far as treatments go--just Google--but it's a question of how much tolerance you have for potential toxicity and environmental effects.

Personally, I used an organic copper fungicide last year, and it slowed progress of disease. I had a good harvest. This year, I am alternating Serenade and the organic copper, spraying one or the other every week. There are no signs of disease on my plants currently, but I wouldn't be surprised if I did get spots later in the season. But later is better for getting good harvests, and I expect disease progress will be much slower than if I did not spray, which is also key to getting good harvests.

Diseases like this are so common and are in the soil and on the wind. They're hard to avoid. In some regions, keeping pristine, disease-free tomato plants is just not realistic, and it becomes more about managing disease so that you can get good harvests despite it.

Hope that helps.