I've got a cherry tomato plant that's doing pretty well, but the beefsteak and roma right next to it are having a lot of leaf trouble. They all seem to be fruiting well, but the leaves seem to be burning. I think I've been watering enough (everything else in the same garden is on the same soaker hose and is doing OK - on every 2 days) so my first thought was maybe they are getting a bit too much sun. The soil isn't great though, so lack of fertilizer could also be an issue. Is there a way to tell which? I've just added a light shade to diffuse the harshest afternoon sun to see if that helps.

I'm in the foothills of Colorado, so in the 90s F/30s C for the last several weeks with basically full sun every day and low humidity. The soil is also sandy and not great, though I've got these in a raised bed with drainage and some added compost and vegetable fertilizer.

This picture is the beefsteak, which has a really bad section but the rest isn't too bad. The roma has a lot more fruit, but about half the leaves have a yellow/brown 'burn' around the edges.

enter image description here

1 Answer 1


If you didn't use sterile soil in your raised beds and/or if you've put the tomatoes in the same bed they were in last year, then I'd say your tomatoes have one of several possible fungal infections. This is especially true if you're growing heirlooms which have almost no genetic resistance to early blight, late blight, verticillium or fusarium infections. The cracking shown in the ripe tomato in the lower left of the photo is also a possible indication of too much or uneven watering.

  • This is a new bed with new soil, so fungus I think is unlikely, but definitely a possibility sink I can't trust the source, so I'll look into that more (no heirloom species). When you say uneven watering, do you mean uneven in time or in space? Both are probably true - I didn't set up my soaker hoses very well and I've been adjusting the timing to figure out how much I need. I just reduced the watering time so maybe that will help. Commented Jul 14, 2020 at 6:40
  • If you used any native soil rather than a soilless mix, it's still likely to be a blight/fungus of some kind. What variety of tomatoes did you plant? Your non-heirloom tomatoes are likely immune to some of the nastier fungal diseases, although still susceptible to early and/or late blights. "Uneven watering" can be something like watering an inch a week (two waterings of half-inch each) and then getting a 2" rainstorm after a four-day dry spell. It mainly affects nearly ripe fruits, by splitting them.
    – Jurp
    Commented Jul 14, 2020 at 13:31
  • In the past couple months the cherry tomatoes are doing much better. I trimmed off some of the dying bits, but I think the main difference was the more regular watering and a bit more fertilizer. There are still a few branches turning brown here and there, but the plant is huge so it's no big deal. The beefsteak (the only heirloom I had) basically died though. Probably a disease, but also the cherry tomato got so big that it shaded it. I'll try again next year maybe with any heirlooms in containers, and better spacing. Commented Sep 14, 2020 at 3:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.