Bottom of tomato is rotten

Tomato Rot On The Bottom ( What Is It? ) “Blossom End Rot”

Bottom of tomato is rotten with Blossom End Rot
(A picture of my tomatoes with rotten bottoms (blossom end rot) ) 

A surprising number of my tomatoes this year had developed what looks like tomato rot on the bottom. I’ve never seen this before.

What happens is the bottom part of the tomato starts to appear sunken and dark. It literally looks like it’s rotting. The dark spot gets larger, up to 1/3 or even 1/2 the diameter of the tomato. It happens on green tomatoes and red tomatoes.

I estimate that 1/3 of all my tomatoes had this condition!

Have any of you seen this before?

UPDATE: I found this product to help stop blossom end rot:
Blossom Rot Spray

Although I ultimately ended up with a decent harvest from just 8 prolific plants – including the green tomatoes due to a killing frost (five 5-gallon buckets – about 125 pounds), it was unfortunate to throw so many away due to this condition.

Here’s another picture of ‘blossom end rot’
Blossom End Rot

Carrots Love Tomatoes:
Secrets of Companion Planting for Successful Gardening

What is it?
After searching the internet for this ‘rotten tomato’ condition, I discovered that it’s called Blossom End Rot.

At first I thought it was some kind of plant disease. No, it’s not a disease.

It’s a calcium deficiency.

“A tomato’s cells need calcium to grow. Calcium acts like glue in cells – it binds them together.”

Why did it happen?
My next question was, WHY?

My first thought was soil. No, they say it probably is NOT the soil. Most soil has plenty of calcium.

The problem is with the ability of the tomato plant to uptake that calcium. Here’s the best explanation that I found:

Tomatoes absorb calcium through water. But calcium isn’t fast-moving.

If a tomato grows quickly, or if other conditions slow water absorption, then calcium doesn’t have enough time to travel through the whole piece of fruit.

Evidently there are a number of conditions that can slow or inhibit that process.

– Tomato plant grows too quickly
– Cold temperatures
– Cold soil
– Inconsistent watering
– Excessive heat
– Root damage
– Too much nitrogen in soil

The Week-by-Week Vegetable Gardener’s Handbook:
Make the Most of Your Growing Season

Why did my tomato plants get blossom end rot?

I suspect it might have to do with a few things. But I’m not sure.

– I live in the north. It’s cold up here more than it’s hot. Early in the season the soil was on the cold side (although the tomato plants were in a raised garden bed which helps warm during the day – but also cools quicker with any lack of sunshine).

– Mid summer we had periods of excessive heat (very unusual for us) with several official ‘heat waves’.

– The tomato plants grew prolifically. These plants had thick stalks and branches. Very stout and they grew like crazy. perhaps too fast?

Cosmonaut Volkov Tomato
I just wanted to mention that the variety I chose this year was one of the best tasting tomato I’ve tried. I chose these due to their ability to grow well in cold climates and fairly short time to harvest (we have a short growing season up here).

We’re making sauce with our harvest (canning). I wish there was a way to have fresh home grown tomatoes year round!!

Tomato Knife by Wusthof (Top of the line)

More: Ways To Tie Up Tomato Plants
More: 5 Methods of Home Food Preservation


  1. You can get Blossom End Rot on squash, too. It is caused by not enough calcium.

    I tried adding egg shells to my soil, but not enough calcium was absorbed. In fact, most of the egg shells didn’t decompose. So this year I bought calcium spray (Rot Stop) to spray directly on the plants and fruits as they grow. That worked for the tomatoes, but this year all my zucchini flowers were male so I got no zucchini. I don’t know if the extra calcium caused that.

    1. Calcium nitrate is what you need. It can be found in most garden shops. It is inexpensive. It dissolves easily in water. It is taken up by tomato plant fast. Water each tomato plant with 2 tsp. dissolved in 1 gal water when plants start blooming. This will stop blossom end rot.

      Calcium Nitrate

  2. I also have a problem with Bottom End Rot on the Tomatoes almost every year, mainly from to fast growing and HOT! I just pull em and toss in the Compost Bin.

    BTW Epsom Salts are NOT for BER, old wives tale that is actually counterintuitive for the problem.

    The problem exist with most every variety of Tomatoes I try. Maybe I’ll try a super dose of Calcium next year, and use throughout the year.

    After all a Garden is always an experiment in progress :-)

    1. I don’t throw any part of the tomato plants in my compost. The diseases associated with tomatoes goes into your black gold you are producing. Also dig deep to remove as much of the root system as possible.

  3. Would lime help with this? The main ingredient is calcium carbonate. I till in lime, manure and compost every spring.

    1. Doesn’t lime raise the ph? Tomatoes need soil between 6 and 7 — best closer to 6. I think you would not want to add lime unless your soil is VERY acidic, maybe around 5.

      1. I don’t know about the ph level. I just do a light dusting and till it in.

        1. There are some really cheap home test kits for soil ph. The county extension dept will also do a soil test. Soil that is too “sweet” (alkaline) can be as bad as too acidic.

        2. I didn’t think about it earlier but anyone that attempts to garden would be wise to do a real soil test. It will identify any nutrient deficiencies or surpluses. You will know what to add and how much to use for whatever crop you desire to grow. County extension office is a much under utilized resource.

  4. I looked up Blossom End Rot at the Old Farmers Almanac site. Too much useful information to type here. Worth a look. Doesn’t only affect Tomatoes. Even the type of Nitrogen Fertilizer can affect how Blossom End Rot hits your plants.

    I got lucky this year very little End Rot and I used Epson’s Salts like my Grandmother would say. Might not have made a difference one way of another.

    1. NHMichael, I also started seeing odd coloring on my tomatoes and did one watering with Epsom salt dissolved in it. No more problem. We had lots of heat this year and less water than usual for long spells

    2. DAMedinNY one of the things mentioned in the Old Farmers Almanac site about Blossom End Rot was water stress (too much and too little?) and mentioned using mulch to help retain water. Seems too much water is also a problems with Calcium uptake thus the Rot issue.

      I remember you telling me about Red neck Raised Beds with bottomless 5 gallon buckets for peppers. Maybe that would help with excessive rain in your area? Here in NH we get a lot of rain then very long spells of no or little rain. So thus my concern about drowning them early on before hot and dry?

      Or maybe you could use the 5 gallon self watering buckets? Mine worked really well with my tomatoes and Basil mixed in. Early on I could fill the water reservoir every few days and later when hot and dry during fruiting season I would dump a gallon almost daily into it. I was worried when we got some toad downers rain storms that I’d have flooding but the weep hole kept the water level ok.

      Right now I am looking at after I take the tomatoes out for the year putting a lid on the bucket of soil for next year. Thoughts? I’ve had no sign of late blight yet and generally I move my tomatoes every two years or until blight shows up. Opinions and experience welcome!!

      1. NH Michael, one of the other issues I worry about is planting the same item into the same soil the following year….so I try to rotate everything on a three year cycle, then total rest for the area in the fourth year using s cover crop only is my plan. So with the large containers, I would have a hard time following the planting of tomatoes in containers with root crops (lacking space), and then beans and peas. And we are not supposed to have tomatoes or white potatoes follow each other…I guess the same bug types or diseases with both of these although they are in different crop groups. With the bottomless black 5 gal containers, I could place them in the different soils surrounding the plants that small creatures were chewing (peppers primarily and tomatoes).

        That being said, I am about ready to put my sweet potatoes into the large 15 gal containers with holes drilled in the bottom because the minute they appear large and ready to dig out for us to enjoy, voles eat them! And they do the same with my beets!

        Our plan for this summer was to create a raised bed system around the 50 X 60 ft Garden area so I could place hardware clothe in the bottom and add covers to the tops to easily extend or start growing season. This inside garden area also serves as a holding pen for my young grow out piglets in the heavy snow season. So the soil within the garden is well tilled and fertilizer and then rested for 60 days before I plant. The raised bed outside would be fertilizer by me,placing my chicken poop or goat poop straw and any other compost I have available. Needless to say, it has not yet been completed due to a LOT of extenuating circumstances this summer.

        5 gal containers need much closer attention that my hillbilly raised beds. In fact, as things got out of control this summer with poor weather conditions, excellent soil conditions, and many personal family/friends illnesses and passing, I decided to let things work out as they would in the garden. It looked like a hidden survival garden at one point. It did give me an idea of how things might possibly grow without much attention during a less water weather pattern. I still received a reasonable return on most of my veggies – other than the things the voles ate.

        I also have to say that anything planted in my hugels (logs with branches, then straw, then topsoil, top dressed with more chicken poop straw) grew well even without any water.

        Also, I did have crushed egg shell in the soil where tomatoes were planted but it takes a couple cycles for those to breakdown, which is why I also used the Epsom salt when I saw discoloration on the tomatoes.

        I don’t consider myself a knowledgeable gardener…I am still learning so much. I try to observe everything to see what works well and what doesn’t. I try many things others have suggested here also. When I have repeated successes, I continue with what has worked well for me in my soil conditions here at the Farmstead. But each year brings a new battle with all creatures great and small and weather that varies. Life happens! Thank goodness for deep pantries and friends who are willing to exchange veggies and animal meats for what they need.

        I don’t know that I would place a plastic lid on the plastic buckets you mentioned at the end of the growing season. I might consider a mulch type covering, but I like the soil to be able to breathe. Lots of living organisms that still need water, air and light in my mind. I just leave my containers like that open and “weed” them in the spring.

        1. DAMedinNY from what I’ve read and experienced eggshells and ground up bones after bone broth is made is for Next Years tomato crop. They need too much time to be available to prevent blossom rot this year. The Foliar Sprays are much more available today for calcium uptake. Epson Salts seem to increase rate of calcium uptake but again more like next years benefit. More evidence needed. And as I garden with a eye to post SHTF how much foliar spray and Epsom’s salts can I get then?

          Hugel Culture is an awesome way to use rotting wood to boost both drainage and water retention during dry seasons. Just like the forest floor effect. Have you ever heard Sepp Holtzer speak about that? You can view seminars at Permies Dot Com. Lot of work but awesome permaculture results for decades.

          I’ve been talking to neighbors who also have voles and the consensus is get a Ratter Dog to have long term results. The dogs diggings if properly socialized and not Neurotic digging will be far less than voles destruction.

          Thanks for the lid thoughts. I agree a mulch will do much better then I suspect the nightshade soils can go towards my next Hugel. The deck garden or kitchen garden as some call it gets the most attention. Nice that I am still giving away tomatoes today in NH.

          Praying for one more year for more garden and pond preps to be compete. Praying for our Republic to weather the chaos.

        2. NHM, Yes, I have been reading Sepp for a few years – love his ideas hence my hugels. Very natural approach. the herb garden is on one and just goes crazy producing.

          Yep, sending a load of beautiful tomatoes to the local Rest Home today. The older residents love getting fresh! I have stocked Epsom salt, but I am also hoping that as I use my four year cycling process, the soil will continue to build and get better. I also have the advantage of having lots of woodland to gather mulch if needed down the road. I don’t want to rely on sprays for long term results so currently working around what benefits through natural processes. Even releasing some of the bugs (Praying Mantis and true lady bugs) in the area in the effort to balance what was missing. I want to garden now how I may be forced to garden in the future, but using the mechanic equipment that is currently available to help me out time wise, which means I still use a rototiller if I haven’t had the pigs in an area….and I use post hole digger on tractor to dig for the trees and bushes planted.

          I will keep that thought in mind about the ratter dog. I actually had a Bedlington Terrier years ago that was an amazing ratter and ground hog killer, and just as sweet as the day is long. Very obedient and smart also. I must be careful though because that type of dog will also try to go after my piglets and other creatures so lots of training and watching. Personalities of each dog always come into play.

          Yes, pray for the Republic! I would prefer never seeing our downfall in my lifetime, but want the assurance that I am ready if it happens. Meantime, we eat well!

  5. Glyphosate induced micronutrient deficiency. Research by Dr. Don Huber. Is anyone using spray containing Glyphosate. Live next to someone using it (as in wind drift or overspray)

  6. Bone meal for blossom end rot. Blossom end rot is just one of the pitfalls of tomatoes in these parts. Weather is a large factor.

    1. Anony,
      You could probably use milorganite, or other additives to your soil to try and balance the PH. I think milorganite is used to increase mostly the iron and manganese??? Understand that raising or lowering the ph of any soil more than a few tenths (.1) will take a fair amount of material. Only really feasible in something like a raised bed. if you have to acidify or ‘sweeten’ a whole field, it is going to take a whole lot of time and a whole lot of $$ in materials and may be virtually impractable. Case in point: Where I live it is fairly alkaline soil, in the 7.8-8.0 range. My grapes have a hard time up-taking micronutrients in this Ph range. It would be almost impossible for me to acidify the soil by adding amendments to get it back into a good range (6.5-7.5). So, I have found that spraying micronutrient in “foliar sprays” is a way I can get my vines the nutrients they need to produce and be healthy. Mind you, this is only for one type of grape in one 2 acre block, the other blocks are fine. But I spray them all, just to help them along. It is the price I have to pay to live with the soil here. Maybe micronutrient sprays on the tomatoes to get them what they need would be an idea to try. Also might try and find a natural ‘anti-bacterial’ to spray and kill the rot organism on the plants. Just my thoughts on farming in the West.

      1. milorganite is a natural fertilizer. The soil here is acidic, we regularly use lime on crop and pasture land to sweeten soil to the tune of 1 to 2 tons per acre. Lime in bulk is relatively cheap. Dispensed with spreader truck.

    2. AH HA! I live in north central Illinois (“the armpit”) and I get this problem on the first waves of tomatoes every year. Did some research and added bone meal and milorganite this year and barely had any problems compared to years past so “anonymous” hit it out of the park…

  7. The Long Term Solution is Good Soil Health Management. Rotating your crops on a regular basis and also allowing for 1-2 growing seasons of rest and regeneration. Allow the soil to rest for a season then seed for cover crops. I like Sunflowers they are pretty and fix Nitogen into the soil then till old stocks and roots back into the soil. Added bonus cut fresh flowers for the wife and bring indoors major brownie points there…

  8. Also know that Tomatoes should be rotated to different areas each year and never planted in the same location just like potatoes.

  9. Bonemeal (calcium) makes more sense than Epson salts (magnesium).
    But if it works, don’t fix it 😉

    1. If im not mistaken the Mg aids Ca uptake in plants, depending on a few orher micro nutrients, but i know the mag is a big part of KMag and a few other products for helping crops

      1. Tommyboy, Yes, just like our bodies need the magnesium to help with the calcium absorption. This area is also selenium deficient which means our body needs additional selenium and so does my planting ground.

        Perhaps when the spraying stops, the ground will return to normal after a few years – how God created it in the beginning.

        1. DAMedinNY
          There is no substitute for organic matter,
          Yall have an excellent source there in leaves!
          Tons and tons of fall leaves, they are excellent for increasing beneficial microbial activity in your soils, and surprisingly also release a lot of nutrients back into your soil.
          Dont have leaves? Know any landscape folks who do a lot of raking on commercial or residential properties?
          Just an idea,
          Some folks are really picky about chemicals, i get it, but think about the organic matter you could get. The guys over here have to pay at the dump to get rid of all that stuff, ive been thinking about starting a little compost project here with a Mexican guy who lives across the street and hauls tons of small stuff to the landfill, im not picky about chemicals though, different mindset. Organic matter is organic matter and unless its from a big factory farm your most likely ok. Heck we get tons of stuff in the air anyway.

        2. Tommyboy, we are so blessed to have 60 percent woodland on our property so leaves galore! And I use them. Lots of goodies in them and the broken down wood pieces.

        3. DAMedinNY
          Excellent! Sounds like your on it, i have relied heavily on cover crops to build organic matter, just now starting to see progress, oh how nice it would be to have seasonal trees heavily planted on my borders!

  10. If uptake is the problem, the Chelating fertilizers are designed to help with the uptake.

  11. I don’t know which makes me laugh more, some of the comments or the spellchecked comments! Some are very hilarious 🤣

  12. Keep those uniformed voters away from cheating fertilizers! Haha!🤣

  13. Some of my carrots have crown rot which is caused by a pathogen in the soil. Guess I’ll be doing some research during the winter months. As NRP says, gardening is an annual experiment. Good thing we are all such optimists!

    1. Skeezix do you write down your garden plans as to see what worked and what needed change?

      I am too forgetful to know if I planted tomatoes or other nightshades in that area in the last three years. Until I started doing a garden book with planting maps and notes I had some awful failures from Early and Late Blight in my nightshades (tomatoes, potatoes, peppers). Some smart Chinese Guy said “the faintest ink is better than a strong memory”.

      You maybe planting those carrots in the same spot year after year and soil diseases were waiting this year.

      ANYBODY have a recommendation for the best and second best home soil test? Reading reviews on Amazon I’ve found none well recommended.

      1. NHM – sorry I am unable to help on this matter. I don’t use test kits. I prefer to observe how things are growing and think about the order of planting what first based on how the land was used before. I kept salt water aquariums with live corals, invertebrates, and fish for almost 25 years and never tested the water. Used a very simple set up and OBSERVED. Made sure everything was happy and it was extremely successful. I was able to sell aquarium cuttings of my corals regularly to salt water fish stores. Even my bubble anemones reproduced! I kept it simple and observed. That is how I want to keep our farmstead – as natural as possible using items that will always be available no matter the state of our fragile union.

  14. I to had a lot of blossom end rot and all kinds of odd diseases I have never had before. My bell peppers also had blossom end rot.
    You can grow tomatoes all winter, in a flower pot in the house. Works great.

  15. Tomatoes do not need acidic soil, or they would DIE here. I have to laugh at the youtuber (who shall remain un-named) who insists that tomatoes, squash, and even pine trees can’t survive in alkaline soil.

    That said, there is plenty of most nutrients in most soils. They’re just not bioavailable to the plants. The best solution is a strong fungal and bacterial network to make them available.

    1. Lauren, I like the idea of being able to grab a handful of woodland soil which has an abundance of the fungal activity and microbes we want and place it where it may be needed. Still experimenting with this but does seem to be working.

      It is pouring rain here so I am grabbing a little more MSB time right now.

  16. I too live way up north, and also have a problem with blossom end rot. Not to bad this year, but still had some. I have a simple suggestion you might want to try with one or two of your tomatoes next year. Try pushing 4 or 5 plain tums around your tomato plant about 3 0r 4 inches from the stem when you plant it in the ground. Push them down 1 or 2 inches, and make sure they’re plain tums, not flavored. Put in a couple extra plants, just in case, but should work. Also, I usually spread a thin layer of wood ash over my garden every other year along with fertilizer, etc. before I rototill. It definitely helps. It also seems to get rid of those tiny worms that eat the roots on your root crops. I too, keep a bottle of that blossom end rot spray around.

  17. Epsom salt stops blossom end rot in its track.s is a magnesium deficiency.. I melt it in water according to package instructions and apply to each plant. .

    1. Just Sayin’ – it seems to work for me as well. Just hoping to get soil in better condition before salts are not available.

  18. Last year when the rot seemed to want to start, I started adding crushed egg shells and it stopped the rot.
    This year I solved the blossom end rot by simply adding egg shells to the initial soil. I have beautiful tomatoes from 5 different plants grown in one flat. (A Mother’s Day present.)

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