People speculate that blossom end rot in tomatoes and peppers is caused by a lack of calcium in the soil. Many now suggest that dropping a TUMS (common brand of antacid) into the soil below each tomato or pepper will prevent this problem.
Will TUMS cure blossom end rot (BER)?
This is a very good example of a myth that can be debunked very easily, knowing nothing about BER.

What Causes Blossom End Rot?
BER is caused by a lack of calcium in the fruit. The plant may have lots of calcium but if the plant does not move it to the fruit, the fruit gets blossom end rot.
From this last statement it becomes clear that soil with enough calcium in it, might still lead to BER. Soil that is deficient in calcium, which is not very common, will lead to BER because the whole plant can’t get enough calcium.
Why does a plant not move enough calcium to the fruit? This is still not fully understood, but watering has a lot to do with it. Either too much water, or not enough water will cause BER. The best way to solve the problem in the garden is to water regularly and mulch to keep moisture levels constant.
BER is more fully discussed in Blossom End Rot.
Will TUMS Cure Blossom End Rot?
TUMS contains a significant amount of calcium. If soil is deficient of calcium TUMS will certainly add calcium to the soil, which is then available to tomatoes and peppers.
Calcium deficiency is not a common problem in soils, so for most gardeners, TUMS will have no effect.
Lets assume a soil test was done and the soil is deficient of calcium. How many TUMS does it take to bring the soil back up to adequate levels?
The number will depend on the degree of deficiency and the target level you want. Spectrum Analytical provides a guideline (ref 1) and suggests adding between 500 and 1,500 pounds of gypsum per acre. Let’s go with 1,000 pounds per acre. Gypsum is 22% calcium, so we need to add 220 pounds calcium per acre.
An acre is about 44,000 sq ft, and 220 pounds of calcium is 99,660 g. Each sq ft would require 2.3 g.
The generic brand of TUMS on my desk has 0.75 g calcium carbonate per tablet which is 0.3 g of calcium. So you would need to add 7.6 TUMS for each sq ft of soil in order to add the necessary calcium.
A 10 x 10 ft garden (about 9 sq meters) would require 760 TUMS.
Does this sound like a cost effect home remedy for your garden? What effect do you think the common recommendation of one TUMS per plant has?
This is such a silly myth that it has upset my stomach – good thing I have TUMS handy!
References:
- Calcium in Soil; https://www.spectrumanalytic.com/support/library/ff/Ca_Basics.htm
- Photo source; Dave Lundy
Is it safe to add a small amount of cremation remains to help add calcium to the soil? I have read that there is a good amount of sodium in cremains, but I did add some last year to the soil around my tomato plants, and they thrived. Also, what are your thoughts about adding powdered milk to the soil of plants that fruit with BER? Thanks for your article.
It should be safe, but few soils need more calcium. BER is rarely a calcium deficiency so milk does nothing to solve it.
Tums definitely has cured my BER for tomato container growing with regular granular fertilizing rotation.
I’m a true believer in it after trying BER spray that didn’t work
To each their own..
But I bet you did not do a control?
It does work – just 80 TUMS per plant!
My Ph for the first 3″ is 6.7 below 3″ the meter pegs out at 3. Here is the funny thing. Last years tomatoes were not bad at all. One plant had bottom rot the rest were alright. So we ground up 7 Tumbs from a bottle we had for over 20 years.
Measured 7 Tumbs to be 1 Tablespoon. Ground down the rest of the bottle and had enough for one spoonful for each plant and half a spoon between the plants. Gave them a quick water as we have wind and dust fly’s.
Now you know that it’s not worth doing.
Robert Pavlis you’re doing a great job here.
Thanks for all your hard work.
TUMs also have magnesium… which will help carry the calcium to the plant
Not sure what you mean by “will carry”, but magnesium will not help move calcium closer to plant roots.
a much cheaper solution is calcium sulfate found in gypsum, so find some scrap drywall laying around, pulverize it and……yes, mix with water and apply to the roots.
I treated my squash and zuchini this way.
Since the soil is rarely deficient in calcium, this is not normally required.
You are correct, it isn’t normally required, but if it is, gypsum is cheaper than tums.
This particular plot had been planted 2 years in a row with Cucurbitaceae family, or, more plainly, last year giant pumpkin was grown so I felt there was a depletion.
It worked from what I can see.
From what I’ve seen about tums for BER, it’s being used more for an emergency cure. Crush the tablets & spray the vines of tomatoes that have BER. But the basic treatment for BER, is timely watering, because (as you stated) Calcium is available in the soil, but the plant can’t use it because of a lack of water.
There are several quick fixes for BER, and all of them includes mixing with water. The water cures the BER. 🙂
What about Rennies?Just joking
That’s an interesting article. Yeah, when you got right down to the figures, it doesn’t seem reasonable, at all, to use this method. Not to mention, it’s rather messy and litters the garden w/ all the extra fillers in Tums. lol
I had never heard the recommendation about using TUMS to prevent blossom end rot but, luckily, have not encountered that problem so far.
For those of us growing tomatoes in containers, with perhaps one-square foot of soil at the surface, throwing down 7 or 8 TUMS tablets at the beginning of the season may be as cost-effective as anything else. There are many variables even so . . . I buy TUMS at Costco where they’re quite cheap but if tomatoes need TUMS as frequently as I do, perhaps not.
It’s a bit of a conundrum when you consider that tomatoes are a common cause of indigestion.
But since you are growing in a container, you need to fertilize regularly so you would not have a calcium deficiency unless you select the wrong fertilizer.
what do U mean the wrong fertilizer….. what kind we need to use….
Depends on which nutrients are missing from your soil. What did the soil test show?