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Tomato Pests & Diseases

Drowning tomato? Fungus? Yellowing leaves.. help!

17 years ago

I'm pretty new to tomatoes. This is just my second year with them, and I am probably absurdly trying to stay organic. I got two tomato plants in trades -- a roma and a Sungold -- put them both in pots on the sunny driveway, in almost pure garden/kitchen compost -- I probably mixed in a little promix and composted cow manure -- and put those red plastic soil covers around their stems. I've sprayed them occasionally with water/dishsoap/bakingsoda/milk/garlic oil. They THRIVED. I have plenty of little tomatoes growing, especially on the Roma. UNTIL we got these torrential rains starting Saturday or so. Now I'm seeing these leaves:

What is this? Fungus? Virus? Today I sprayed with a neem mixture, but I don't even have any idea what Daconil is (some of you seem to be spraying with it?) and am about to plunge into a period of intense work for about a week and won't have time to go to the garden center to buy anything, or spray anything, until the end of next week. Is there anything organic I can do tomorrow? Will they survive until next week? We've got weather forecasts calling for more rain, thunderstorms, rainstorms, rain, rain, rain. Should I stick these plants in the garage or on the porch to dry them out a bit? Anything else that might help? Mulch them with a few more inches of compost to stop rain splash? (I don't have any other form of mulch handy) Should I pick off the baby green tomatoes and put them on my windowsill now?

Thank you for any advice!!

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Comments (2)

torquill
17 years ago
They'll survive, Julia... they'll probably suffer a bit more damage, but you'll still have plants next weekend.

It looks like a classic case of Early Blight to me, which is a very common fungus (Alternaria). I don't know whether it came as an airborne spore or splashed up from the soil in the pots, but now it can spread from leaf to leaf by rain splashing on them. If you can protect them from overhead water by putting them under cover, it may help a bit.

What else should you do? First, pick off all of the spotty leaves you can find, or slice off the portions that have spots if that seems too drastic to you. That'll slow it down. Mulching might be good, in case it came from the soil in the pots. Between those measures and possible protection from the rain, they shouldn't take too much more damage before you can get to them.

Daconil is the old name for Ortho Garden Disease Control, a fungicide. As the "Ortho" part suggests, it is not organic... but it has very, very little toxicity for people and animals, and the only concern I know of is with aquatic invertebrates. Chlorothalonil, the active ingredient, is much less toxic than many things we use every day. If you're strict organic, you'll have to do without, and try to find some organic fungicide -- I think Gardens Alive has one, but it's nowhere near as effective as daconil.

If you're a low-impact, sustainable gardener, chlorothalonil is pretty much harmless and fits in with the "no harm" gardening style some of us have. So you should decide which school you're following, and choose a fungicide accordingly.

The catch is that no fungicide is going to work if it immediately gets washed off by rain. So you'd need to wait for a break anyway, should it come before you all get washed away. :)

Good luck.

--Alison
juliat
Original Author
17 years ago
Thanks, Alison! Okay. I'll put them on the porch tonight (it's sunny right now, amazingly) since we're expecting more rains this weekend. I'll pick off the worst leaves (if I took them all off I wouldn't have any left) and if I have time will mulch. Thanks for the advice, again.

Julia
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