Condo Blues: Why Are My Tomatoes Rotting on the Bottom?

Sunday, July 25, 2021

Why Are My Tomatoes Rotting on the Bottom?

I’m attempting to grow tomatoes in this year’s garden. I say attempt because I haven’t had much luck in the way of getting a plant to give me more than a handful of tomatoes any time I plant tomatoes.

I am determined that this summer will be different. I read everything I could find on how to grow tomatoes. I bought a more mature tomato plant instead of attempting from seed and upped the watering schedule.

I was excited to see more  blossoms than I’ve ever had on a tomato plant. I cheered when they grew into green tomatoes.  I was overjoyed when I plucked the first red tomato. Finally I broke our tomato curse!

Until I turned the tomato over and found this.

how to prevent blossom end rot in the garden
 Save this tutorial to your Pinterest boards for later! Share it with your friends!

Blossom end rot!

Vegetable Garden Blossom End Rot What it is, How it Happens, and How to Fix It

Blossom end rot looks like a black rotten and sunken spot on the blossom (bottom) end of tomatoes, summer squash, cucumbers, peppers, and eggplant.


  • The good news is blossom end rot is not caused by a disease, bacteria, fungus, or pests.


  • The bad news is the conditions for blossom end rot were already in the soil when you planted the vegetable seeds or plant – especially if it is a container garden like mine.


  • The best news is after sacrificing a few mature vegetables to blossom end rot you can fix it with soil amendments to grow the rest of the plant and make sure it won’t develop blossom end rot for the rest of the season.


What causes blossom end rot is a lack of calcium in the soil. Vegetables, such as tomatoes grow and mature quickly and use a lot of calcium to do so. If the plant doesn’t have enough calcium throughout its plant system while it is growing, it shows that the plant is stressed out by developing  rot at the growing  part of the fruit. (Yes tomatoes are really a fruit we consider a vegetable!  If it has seeds it is a fruit. If not, it is a vegetable.) Think of it as plant osteoporosis.

what is blossom end rot on vegtables fruit

The white stuff on the tomato leaves is diatomaceous earth. I threw on all of my vegetable and herb plants in an attempt to save them from ravenous  Japanese Beetles. I hate those guys!

Gardening experts say you can fix blossom end rot in tomatoes (as well as the other plants I mentioned) by keeping the soil consistently moist and making sure you have enough calcium in the garden soil that the plant suck up as much as it needs and without being stressed.

How do you do that? Well, the experts say you should have your soil tested and add amendments accordingly. Others swear up and down that using compost as fertilizer will add enough calcium to the soil to keep the tomatoes happy.  I’m not sure where they get that because you shouldn’t compost most calcium laden food waste such as cheese, milk, dairy, and bones. Or maybe the lack of calcium is just due what I personally put in my  compost and yours is fine. (Makes note to self to get next year’s DIY compost soil tested to double check it has all of nutrients my plants need.)

Water is not an issue. I’m like a helicopter mom with checking my container garden for moisture. I haven’t had the soil tested but I’m pretty sure the tomato blossom rot is being cause by too little calcium currently in the soil (which is new out of the bag this year.) I added more calcium to the tomato plants by fertilizing with this exact Espoma Tomato-tone Organic Fertilizer (Disclosure: I am including affiliate links in this post for your convenience.) I chose Espoma because it specifically said 8% of the fertilizer is calcium to prevent end blossom rot and it is not made with artificial ingredient sources.

The almost always droopy leaves on my tomato plant perked up the following day and stayed that way. I’m pretty confident low calcium in the soil is the cause. For here on out I am going to keep adding calcium to my garden soil by dissolving powdered milk (I use it to make yogurt) into the watering can and using diluted milk water to water my tomato plants. You can use regular liquid milk too but that doesn’t last very long around here. Milk is my husband’s favorite sports drink! 



Looking for more tomato gardening tips and ideas? Check out the following options – and more! – below!

Did you enjoy this post? Get more like it by subscribing to the Condo Blues RSS Feed .


Deb mcK said...

My husband always puts gypsum to his tomatoes to help prevent blossom end rot. Good luck!

the next best thing to mummy said...

y husband is the only one in our family who likes tomatoes, I and our sons don't like them#alittlebitofeverything@_karendennis

Post a Comment

I love comments and read them all! If you’re shy and don’t want your opinions made public, you can always email me at condoblues [at] gmail [dot] com.