A Garden Tragedy

June 16, 2011 4:39 PM

What's the matter with my tomato plant?

These brown, scaly patches on the leaves just emerged over the last day or two. See pictures:
Photo 1
Photo 2
Photo 3

The stem seems unaffected, though the unripe fruit (cherry-size) is now dropping off and this plant is very spindly. I haven't used any pesticides, and have used the Miracle Grow tomato-specific blend. And this plant is just a few feet away from another tomato plant that isnt' showing symptoms.

Halp!

posted by BlahLaLa to home & garden (17 answers total)

I rather fear that is early blight. If you get yellowing around the brown patches, I'm sure it is.
posted by cromagnon at 4:45 PM on June 16, 2011

Nope, unfortunately, I believe that's late blight. Early blight creates a sort of yellow scum on the leaves and stems that wipes off on your hands, and actually won't kill the plants unless they're already weakened from something else. You just pull off the leaf stems as they start to turn yellow.

That plant is toast. Pull that poor sucker up. Get it as far away from any unaffected tomato plants as you can.
posted by mneekadon at 5:42 PM on June 16, 2011

Also -- late blight will creep up the stems and into the fruit, turning everything black and leprous looking. Ask me how I know. Most folks will tell you to burn any affected plants.
posted by mneekadon at 5:46 PM on June 16, 2011 [1 favorite]

Which leaves are affected? All of them, youngest, oldest, at the base of the plant, top?

It doesn't look like early blight to me which tends to have roundish areas of necrosis surrounded by chlorosis; nor late blight, but if see browning of the stem as well in weird spots it probably is. Usually late blight is not so consistently interveinal like those lesions, it's more like a dull brown smudge in random places. I'm thinking a deficiency, which is why where it is on the plant is important for diagnosis (especially older versus younger leaves).
posted by oneirodynia at 6:40 PM on June 16, 2011

Here's Cornell's info on late blight and its imitators. Your photos look more like septoria to me, but hey. Toss the plant, toss the soil it's in, sterilize the planter. Do not compost or burn the remains -- it will only spread the virus.

If you'd like a confirmed diagnosis, bring some leaves to your local ag extension service or a plant nursery with horticulturalists.

Please don't send them to me.
posted by vers at 6:45 PM on June 16, 2011 [1 favorite]

Okay, thanks for the advice so far. Oneirodynia, it's the leaves all over, old and new. And it came on suddenly, if that makes any difference.
posted by BlahLaLa at 6:53 PM on June 16, 2011

Here's a great site I use to diagnose tomatoes.
posted by TheBones at 7:03 PM on June 16, 2011

So, the newest, youngest leaves at the top of the plant also have brown spots? That sounds more like Tomato Spotted Wilt, which is spread by thrips. One of the symptoms is necrotic brown spots. The youngest leaves being stunted or discolored is characteristic. You might be able to see thrips with a hand lens as well. It often has rings too, but not always.

Septoria usually begins with lower leaves, and has a characteristic grey spot in the center of round lesions. I'm not seeing that in these photos. However, you can look at the spots with a hand lens and you should be able to see fruiting bodies containing spores.

Anyway, lack of differentiation in parts of the plant that show symptoms point away from a deficiency (and certain diseases). The one other question I have is if you have fertilized recently, or transplanted the plants into soil with fertilizer. If not, I'm thinking a disease of some sort, in which case you should probably yank the plants. Do not compost, and do not reuse the soil.
posted by oneirodynia at 7:31 PM on June 16, 2011

Oneirodynia, I did just fertilize over the weekend with the Miracle Grow tomato blend. I haven't really been on top of fertilizing this season so I don't remember how long it had been since the last fertilizing, but it had def. been at least a month.
posted by BlahLaLa at 7:34 PM on June 16, 2011

Hmm, could be salt burn, but too much fertilizer usually burns leaf tips as well. Here's a pic.
posted by oneirodynia at 7:47 PM on June 16, 2011

Whatever it is, it looks just like the thing that took out both of my tomatoes in under two days. Left Tuesday morning, and by Wednesday night they were covered in spots. I'm strongly suspecting early blight. (The plants are in a planter on a second-story balcony, and they got all new soil this year. I suspect a fungus came in on the soil when I bought the plants from a gardening store.)

I pruned all the affected leaves and it remains to be seen if the remaining parts will be able to make it. This morning they're still alive, but we'll see. But if you have other tomato plants that are currently healthy, it might be wiser to destroy the plant. And maybe treat the other plants with a fungicide? A lot of the major suspects seem to be fungal.
posted by pie ninja at 4:10 AM on June 17, 2011

Okay, everybody. Thanks for the info. I do only have one other tomato plant, and it's just a couple of feet away (they're both in pots). I think I"m going to try pruning the affected foliage today and then wait a couple more days to see what happens. Guess I have to chalk it up to the whimsy of the garden gods.
posted by BlahLaLa at 7:30 AM on June 17, 2011

Another possibility -- has it been rainy lately, or have you been watering the leaves? Could be from water. We had a lot of late rain, and most of the tomato plants in my community garden show the same thing. I removed my affected leaves and the plants have been fine.
posted by mudpuppie at 9:06 AM on June 17, 2011

Mudpuppie -- it has rained a little, but it's been misty and unusually damp, too. (This is L.A. so we're used to it being quite dry.)
posted by BlahLaLa at 10:43 AM on June 17, 2011

Just wanted to update for anyone following: the plant isn't getting worse, no additional foliage seems to be involved, the stems and fruit seem fine. And another tomato plant just a couple of feet away isn't affected. So maybe we dodged a bullet?
posted by BlahLaLa at 9:14 AM on June 19, 2011

Just following up again for anyone checking this thread. It's now a week later and the plant seems fine. It's setting more fruit, no new leaf discoloration, the other nearby plant isn't affected -- this was a bit of a mystery but whatever it is seems to have passed.
posted by BlahLaLa at 11:48 AM on June 23, 2011

Yay! Plants are goofy sometimes.
posted by oneirodynia at 5:46 PM on June 23, 2011