Is this it for this year's tomato crop?

July 28, 2008 7:09 PM

What is wrong with my tomatoes?

I'm growing Early Girls in a pot with some manner of enriched soil on my front porch in Palo Alto, CA. They get sun probably 8 hours of the day and are watered both by sprinklers and also by me, watering from a can. I have not been as consistent as I could have been with watering and because the sprinklers come on at 1am, I'm not certain how thoroughly this plant gets watered. However, it's a huge plant.

A couple of weeks ago I started noticing small yellow spots on the leaves but didn't think much of it, because I was getting dozens of green tomatoes and was too excited to worry.

We got one ripe tomato last week, which was delicious. Today I picked our second ripe tomato...which is worrisome.

It's not like any pictures I can find online. Basically, the blossom end has a bunch of faint black or brown specks, and it didn't ripen. So I have a red tomato with a green and black/brown bottom. I cut it open and it smelled a little off, but I have an overactive imagination so who knows how accurate that is; it's green on the inside corresponding to the green bottom on the outside. I haven't tasted it...yet.

The spots look like the pictures I've found online of bacterial speck, but I haven't seen anything that says bacterial speck can be confined to only the very tip of the tomato, nor that it would inhibit ripening there. What would make sense to be on the blossom end is blossom end rot, but this looks nothing like pictures I can find of blossom end rot. On inspecting the plant it looks like a lot of the green tomatoes have various degrees of the same speckling. I'm wondering if I need to pull these tomatoes off or if this is something I can correct with watering or fertilizers.

If you think you might be able to help if you had a picture, let me know and I'll find a place to put one, or email one to you.

posted by crinklebat to food & drink (8 comments total)

I would guess that it's something like blossom end rot, bacteria or fungus. Regular watering and a calcium supplement to your soil (liquid calcium or gypsum added to soil) would help. It also tends to get better on its own but it slows down production and the first few fruits are usually bad.

Ideally, your tomatoes will be watered daily and live in well-drained soil. Water should NEVER touch the leaves or fruit and the tomatoes would be watered from the roots up. No sprinklers....just YOU.
posted by answergrape at 7:43 PM on July 28, 2008

Sure sounds like blossom end rot. Does the lower centre tomato in this image or the top left tomato here resemble yours?

It can be caused by anything that causes excess growth: irregular watering, excess fertilizing or stressing the plant by letting it dry out. Tomatoes need a lot of water. It is especially important in pots to monitor soil moisture levels carefully as it's pretty easy for a hot dry wind to dehydrate the plant and soil in a short period of time.
posted by Mitheral at 7:50 PM on July 28, 2008

Stop hitting them with sprinklers. Water them HEAVILY each day at the soil only. Don't let the leaves or fruit get wet. Ideally water them in the morning. Worst time to water is at night. Fungus likes the dark.

In a pot, I'd fertilize them every few days with a balanced water soluble fertilizer... like Miracle Gro.
posted by jeff-o-matic at 7:57 PM on July 28, 2008

Mitheral, it's hard to tell from those pictures, but I guess it's closer than anything else I've seen.

Guess I'll change to watering in the morning! And try to move them away from the sprinkler heads.
posted by crinklebat at 8:24 PM on July 28, 2008

Sounds an awful lot like blossom end rot - there are a lot of sprays that help this. Or next time you make eggs, sprinkle the egg shells in the soil. Calcium will really help out.

As for the yellowing of the leaves, it's hard to say much about them without seeing them, but if it's towards the bottom of the plant, I'd say you don't have much to worry about.
posted by OrangeDrink at 9:49 PM on July 28, 2008

Consistent watering has been the biggest factor in the BER issues I've had with tomatoes. When I get a little sloppy/tired of watering every day, that's when it seems to happen. And yea, use just the can, at the roots.
posted by cabingirl at 6:53 AM on July 29, 2008

Nthing the blossom end rot diagnosis and never letting water touch the leaves or fruit. I've also heard that epsom salts in the soil can help stop or slow the process so you might give that a try.
posted by mygothlaundry at 7:36 AM on July 29, 2008

Could also be early blight, which I find to be more common than blossom end rot, and tends to produce leaf spotting as well. You might try an organic fungicide, like this one.

Or the leaf spots could be early blight and the fruit spots could be blossom end rot. It probably won't hurt to add some calcium either way. Just don't ignore the leaf spots completely while you're worrying about your fruit. At the least, trim off spotted leaves and do get it away from the sprinkler.
posted by rusty at 7:56 AM on July 29, 2008