My tomatoes - they've got the black lung.

August 6, 2012 6:38 AM

What has happened to my tomatoes? And can I save the rest of the poor things? First time gardener inquiring within.

So, I finally have a house with a backyard and I decided to grow a garden. I went to Home Depot and I bought a raised garden bed kit and some soil and some plants and some vegetable food and and over the course of the summer I have watered and fed and cooed lovingly.

But something horrible happened this morning.

So, I have a couple tomato plants. Most of the tomatoes are still a youthful green, but a couple have turned red.

I made a horrible discovery this morning when I actually made a closer inspection of these red tomatoes.

On the bottom they look like this!

That's not good! That looks like... rotting death? I mean, it looks like rotting death, right?

So, I plucked them off the plant. On top, they look fine. On the bottom, rotting death.

What is this? What could have caused it? Is it something that could spread to the other tomatoes? Over the course of the summer I've treated the plants with "vegetable safe" pesticides about three times... could that be the culprit?

WHY, VEGETABLES, WHY.

posted by kbanas to food & drink (16 answers total)

It looks like blossom end rot to me.
posted by needled at 6:41 AM on August 6, 2012

Some additional info on BER (PDF file) from Michigan State University extension program. The pictures of the tomatoes in that MSU PDF look like yours.
posted by needled at 6:46 AM on August 6, 2012

It sounds like it's a soil issue and you might not be able to prevent it on other tomatoes. But if the top half of the tomato is fine, there's no tomato gardener I know who would hesitate to chop off the nasty bit and eat the remaining tomato. I do this for insect damage, splits, bruises, etc., and the flavor of the rest of the tomato is usually unaffected.
posted by Miko at 6:52 AM on August 6, 2012

Also, next year you could try planting 2 or more different species of tomato and interplanting with marigold, rosemary and/or basil instead of using the pesticides. All of those strategies really help ward off pests. I haven't needed to use any pesticide on my tomatoes in 7 years of gardening.
posted by Miko at 6:54 AM on August 6, 2012

BLOSSOM END ROT, MY OLD NEMESIS. Or, well, my first-time nemesis.

It seems like it is something that will either impact the first couple tomatoes of the season and go away or I have a serious imbalance in the soil that will totally fuck up my shit. Either way, looks like not a lot to do at this point.

I will diminish, and go into the West.
posted by kbanas at 6:57 AM on August 6, 2012 [1 favorite]

I've been planting tomatoes in less than optimal conditions for 7 years. I very occasionally get blossom end rot if the soil has gone through cycles of getting dried out too much/getting too wet, but it doesn't affect all my tomatoes, just some of them.

I always put in a crushed egg shell when I plant my seedlings, and that seems to help. You might try putting in a crushed shell at the base of each plant now, being consistent about the dampness of the soil, and this might help any remaining fruit you develop this year.
posted by maudlin at 7:05 AM on August 6, 2012

Blossom-end rot, yep. Don't blame yourself too much, it happens to the best of us sometimes, especially with the first few fruits that ripen. Make sure you're not letting your potting mixture dry out (that's what you mean by "soil," right?), tomatoes can't absorb calcium without moisture. Now would be a good time to top off your container with some compost, too.

Chop the nasty bit off and feel free to eat the rest of the tomato.
posted by desuetude at 7:10 AM on August 6, 2012

Make sure you're not letting your potting mixture dry out (that's what you mean by "soil," right?)

Yeah, I went to Home Depot and bought four giant bags of potting soil marked for veggies. It seemed like good times.

I try not to let it dry out - I water it once a day, more or less- and feed it every Saturday.

Anyway, I have not ventured into composting and egg shells and things... I was starting small, but perhaps it's time to investigate.
posted by kbanas at 7:13 AM on August 6, 2012

The compost tea suggestion seems like it couldn't hurt, either.
posted by Miko at 7:15 AM on August 6, 2012

You need gypsum
posted by notned at 7:33 AM on August 6, 2012

Blossom end rot is weird. I have it on the first batch of my green zebra tomatoes, but not on any other tomatoes. I also had some on my bell peppers. It was super hot and dry in early July, so that's what did it for me (I also have some heat-related cracking on my larger slicing tomatoes). I added some leaf and grass mulch to keep the soil from drying out, and things are looking much better for the next round of tomatoes. Good luck as you wait this out!
posted by Maarika at 7:42 AM on August 6, 2012

What is the vegetable food you are using? What is the NPK composition? Excess nitrogen can also contribute to BER.
posted by needled at 7:47 AM on August 6, 2012

If you're new at this, it's quite likely that (a) your soil is too shallow and (b) you're using too much fertilizer. Try adding a three-inch-thick layer of pine bark mulch.
posted by flabdablet at 8:19 AM on August 6, 2012

We solved our issue with blossom end rot by putting some epsom salts around the base of each plant.
posted by tigerjade at 8:22 AM on August 6, 2012 [1 favorite]

Egg shells, all year, are what we have done. Yet, on one of our plants this year, we had blossom rot on the first few fruits, and are somewhat stressed about the rest.
posted by Danf at 9:06 AM on August 6, 2012

We solved our issue with blossom end rot by putting some epsom salts around the base of each plant.

That is Magnesium sulfate, not calcium. It won't do anything for blossom end rot, though they are great to use for magnesium deficiencies. If you had end rot you had a calcium deficiency. it probably solved itself, see below.

I always put in a crushed egg shell when I plant my seedlings, and that seems to help. You might try putting in a crushed shell at the base of each plant now, being consistent about the dampness of the soil, and this might help any remaining fruit you develop this year.

You need gypsum

Neither one of these will help at this point. Calcium amendments take a minimum of three months to be broken down in the soil and made available to plants. (You can buy very expensive calcium foliar feeds that are taken up more immediately, but must still be applied before fruit set. End rot is often self correcting and they aren't worth it.) Often times people experience end rot on their first tomatoes, add calcium amendments, and suddenly their tomatoes are okay, so they think that the calcium helped. In reality what usually happens is that by the second crop of tomatoes, calcium distribution throughout the plant has balanced. Tomato fruits have received the majority of their calcium by the time they are the size of a thumbnail. it was in the weeks prior to that time that problems occurred, either due to weather and inconsistent soil moisture, setting out plants too early in the season, or very often due to excess nitrogen causing greater top growth than root growth. Calcium is distributed through the plants as they respire, and with more leaf surface area you have more respiration. If the young root system can't take in enough calcium to keep up with distribution through the plants by respiration, you have calcium deficient baby tomatoes. Usually the root growth increases as the tomato plant grows, and calcium problems are solved. You can't do much about weather, but water consistently and do not use nitrogen on tomatoes unless you are correcting a known imbalance in you soil. In that case, using NH4+ is a better form of calcium than NO3-.
posted by oneirodynia at 4:41 PM on August 6, 2012 [5 favorites]