What is happening to my tomatoes?

Hi, I am on my first year of starting a container garden on my deck in Brooklyn. I have a few different kinds of tomato plants in large pots and they seem to be healthy. Now that I have some unripe tomatoes coming in and growing, I have noticed that on a few of the plants (notably, the "Big Boy" variety as well as some smaller tomatoes I am not sure of the name, but they look like grape tomatoes), the bottom of the tomato is turning blackish, even though the rest of the tomato, and the plant, looks healthy. I have attached a picture. Is anyone familiar with this problem and know what I can do about it? I'd appreciate any help, I want some healthy tomatoes! Thanks :)

It's called blossom end rot, indicating a lack of calcium available inside the plant. The underlying problem might be shortage of calcium in the soil, or might be widely varying soil moisture, which causes the plant to be unable to take up the calcium that's in the soil.

Doesn't harm the plant long term & I've eaten the fruit that ripens that way (cutting off the bottom, of course).

A soil test is the sure way to determine if the soil is calcium deficient, or you might just add a little lime to the soil. As for a good watering regimen, I've never been successful with container planting so the folks who do that a lot of need to advise.

I use a calcium product called "Enz-Rot Blossom End Rot Concentrate" spray
from a company called Gardens Alive. Works beautifully and I never have
had end rot since I began using it. You can probably find a less expensive
version elsewhere but they have a lot of products for organic gardening and
I've been ordering from them for several years.

Thank you so much for the information! I was so puzzled. I am glad to know that it's pretty easily fixable. Thanks again for your time.

More good news is that it for some reason seems to affect the early fruit and then just goes away. I find if I do get BER, and I rarely do, that the later fruits are unaffected. Good luck with your 'maters!

I recommend spraying with the following solution: 1 tablespoon of epson salt to 1 quart of water. All mt veggies are in containers .

Thanks, locakelly! That is great and encouraging news!! :)

Merrymath, is that spray on the whole plant or on the tomato itself? And how often should I do that? Thanks!

Also, keep in mind. That many times even if the soil is perfect. The first fruit does this. If the one in the picture is the only problem tomato - I'd put some epsom salt as describe above and not worry.

Thanks, sgriffith. There are others on other plants that have it as well. Is that epson salt right on the tomato, or on the whole plant? Also, just a one-time treatment, or how often? Thanks :)

Actually, I just apply it to the soil before I plant. But adding it to water will deliver it quickly. I was advising to use the other persons recipe so that you won't burn your plants. I put a tea spoon in the bottom of the holes before I plant.

I spray the entire plant including fruit. You can do this every other week.

Epsom salt is actually magnesium sulfate.


Magnesium ions are required to synthesize chlorophyll in plants. Lack of magnesium ions will result in stunted growth. The leaves will turn yellow. The yellowing of leaves due to magnesium deficiency is called Chlorosis.


Slugs do not like it ... it hurts their bodies.

Organic egg shells crushed into fine powder by mortar and pestle or in coffee grinder. One to two teaspoons at the bottom before planting each year. Prevention

I have enough trouble getting enough calcium myself, now I have to worry about the plants too?? can't I just grind up some of the calcium supplements I'm supposed to take and water with those? haha.

bklynbeginner, you mentioned above you were container gardening. If so what you need is calcium in your soil, not magnesium (as in the Epsom salts recommendation above). Magnesium doesn't come into play with BER (blossom end rot) but it is a matter of calcium not being made available to the fruit.

By the way, spraying anything directly on the tomato itself won't increase the nutrients/trace minerals needed, you'll need to make any sprays go directly onto the foliage and if any is left over then sprinkle it around the root system. (And by the way, for those of you who may have any kind of foliage pathogens/diseases I'd be careful spraying anything if you are having hot, muggy, high humidity weather for fear of spreading the disease.)

Happy Gardening, All!

Shoe (who chowed down on tomato sandwiches for lunch today! Yumm!)

We have been experencing a lot of extremely hot and humid weather. All my veggies and rose trees are in containers. I always do my spraying in the morning. My tomatoe plants are ovet 8 ft tall .... peppers ( which really love the epsom salt) are about 4 feet tall. You can overdo the epsom salt (not really a salt ... but a mineral .... managnesum caltrate you should only spray the epsom salt solution evey other week ... at the most.


I do mix it garden lime and compost with potting soil for all my container planters before planting.

I have also steeped egg shells ang water the plants with the water. I crush the egg shells as best I can and sprinkle around plants. And when I empty a milk container .... Ifill the container with water and water plants. Yesterday I dumpted the water I used to boil corn on the cob into one of the flower garden beds. The Asiatic Lily that received the bulk of the corn water just bloomed today with the most stunning bloom. It is so gorgeous that I insisted that my next door neighbor had to comr over to view it. SHE WAS MOST IMPRESSED.

merrymath, "You can overdo the epsom salt (not really a salt ... but a mineral ... managnesum caltrate"...

Epsom salt is magnesium sulfate, quite different from M. caltrate (usually used as a vitamin supplement for people).

Epsoms sure helps green up those plants though, doesn't it! Sounds to me like you have a great container garden going! Congrats. And aren't those Asiatic lilies the best!

Hope you aren't getting the triple digit temperatures up your way this week. "August" weather is coming back on us again this month!

Shoe