Blossom End Rot

In the world of garden information you can find all kinds of remedies for almost everything that ails your garden. You know how it goes: add a little of this and little of that and it’ll cure whatever problem you’re having at the time.

Bill was talking to a friend of ours the other day who has blossom end rot on his roma tomatoes. Someone had told him the tomatoes needed calcium and to add lime to his soil to supply it.

That kind of advice is a stab-in-the-dark quick-fix for a problem you don’t even know exists.

I’m not sure exactly why we all fall for that kind of thing, especially when we’re new to gardening, but we do.  I did, for at least my first decade of gardening.

Fortunately for me (and for you too if you follow along my path) I finally realized that all you need to do for probably 99.9% of all garden problems is follow the principles of nature. That pretty much takes care of everything including blossom end rot. No need to buy extra stuff or spend extra time with it all.

Just About Every Gardener Has Dealt with It

As I mentioned in a post back in November of 2012, I can’t say that I’ve never had blossom end rot (BER), because just about every gardener has at one time or the other.

In case you’re one of the few who have never seen BER, it’s a brown-black sunken area that appears on the bottom of the tomato.

Thinking back over 36 years of gardening, I remember at least one or two years it was prevalent on my tomatoes. Every once in a while I’ll get it on some of my peppers.

But for the most part, I’m just not bothered with it.

The First Tomatoes to Form Might Have BER (Cause #1)

Most years at least a couple of the first tomatoes that form have BER. According to the folks who research all that stuff, that’s due to the extremely quick leaf growth in the spring and the plant needing more calcium than it can take up. The soil can have plenty of calcium in it, the plants just can’t utilize it that quickly.

When this is the case, the plants outgrow the problem and resume setting perfect fruit.

We’re only half way through tomato harvest and I’ve already harvested over 1,000 tomatoes this season without BER. A very normal occurrence in my garden.

Some Tomatoes are Genetically Prone to BER  (Cause #2)

Paste tomatoes like romas are prone to BER more than regular tomatoes.  I grew opalka paste tomates a couple of years ago and lost several dozen tomatoes to blossom end rot.  The other hundred or so were perfect.

Even some regular tomatoes can be prone to BER.  Make a note not to grow that variety again if you find one that is prone to BER.

Paste tomatoes, window box romas. No blossom end rot.

Paste tomatoes, window box romas. No blossom end rot. All of them have been close to perfectly formed. Picture taken September 4th.



Regular tomatoes with perfect bottoms. Picture taken August 29th.

Fluctuating Moisture Levels (Cause #3)

This is the cause that is probably listed by the “experts” as THE most common cause of BER. The reasoning behind it is that water transports calcium through the plant. Thus, with not enough water, calcium can’t move quickly enough to the fruits.

I think the promotion of this cause makes most gardeners think they can’t grow tomatoes without watering.  I’m living proof that’s not true, along with a lot of other folks who dry-farm (do not water) tomatoes.

We have drought in Virginia every year.  (I thought this year would be the exception, but here we are at the end of the summer and in drought conditions.)  Our droughts last an average of 4 to 6 weeks. Some less and some more.  I’m not set up to water and wouldn’t water tomatoes anyway.  Mainly, because they pretty much tend themselves if you’ve done your job of preparing and covering your soil.

In spite of drought conditions and not watering my tomatoes, I harvest literally thousands of tomatoes that are perfect and free from blossom end rot.

 Other Contributing Factors to BER

The following things are not causes, but rather things that contribute to the main cause which is the inability of the plant to get the calcium it needs even when calcium is already in the soil:

  • Damage to the plants roots
  • Too much nitrogen fertilization by the gardener – I think you’re always better off when you give your soil lots of organic material and let nature worry about supplying the nitrogen in the right amount and at the right time. I’ll be giving some tips on that in future posts.
  • Nutrients out of balance – This usually comes from adding a lot of fertilizers to the soil when you don’t know what you need.  Nature likes just the right amount of things.  If you’re the type of person who just has to add extra stuff to the soil – get a good soil test and know something about what your soil needs before you add it.
  • Water logged soil – This can be caused by poor drainage – The continued addition of organic material to your soil will correct this.
  • Water logged soil  – Caused by over watering – If you feel you just have to water, resist over watering. You’ll  smother the roots and without the oxygen they need they won’t be able to take up the nutrients they need. (One of the results will be BER.)
  • pH that is too low or too high – If you’re doing a good job of adding organic material to your soil, you won’t even have to concern yourself with pH. It’ll moderate by itself. No need to do or add anything but the organic material.)

How to Work with Nature to Avoid Blossom End Rot

  • When initially preparing any garden bed, prepare your soil deeply so roots can easily have more access to water and nutrients.
  • Don’t plant tomatoes too early, when it’s still cold.  If you plant when they can maintain a steady growth rate, it avoids a lot of problems.
  • Mulch tomatoes and pepper plants with at least a 4 to 6 inch layer of straw (or hay or grass clippings). This layer of mulch will prevent sudden changes in soil-moisture levels which researchers list as the principal cause of BER.
  • Make sure you give your soil lots of organic material every year so your soil will be rich in organic matter, drain well, and hold moisture over a longer period of time.
Regular tomatoes. This one plant has already produced well over 150 tomatoes with no blossom end rot.

Regular tomatoes. This one plant has already produced well over 150 tomatoes with no blossom end rot. Picture taken August 29th.

Final Thoughts

As I mentioned at the beginning of this post, you can find all kinds of remedies and quick-fixes for almost everything that ails your garden including BER.

Just remember that nature loves perfect balance.  Adding a little of this and little of that without knowing what you’re doing can cause more problems than it solves.

Getting involved in all the chemistry and complicated details is something I don’t care to do. My part is the easy stuff like

  • initial deep preparation of garden beds,
  • keep the soil covered, and
  • continue to add organic material.

Nature will handle all the complicated stuff for me.  And I can do other things that I’d much rather be doing.


Related Posts:

Watering Guidelines to Consider

Want to Garden Successfully – Look to Nature (on covering your soil)

Adding Organic Matter – 2nd Key to Soil Improvement

A Readers Questions on Soil Prepartion

Soil Test – The Pros and Cons

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  • Thanks for this Theresa! I’ve noticed the same thing–blossom end rot in a few of my tomatoes, especially romas, in the beginning of the season and then no problem. This year I planted watermelon, from seed that usually does well. I had only a few watermelons and they all had blossom end rot. I think they had other problems too – too crowded out by other plants with not enough room to grow and too shaded by the corn!

  • In your August 29th picture of tomato plant – what variety is it. My plants have lots of dead and dying leaves at the base & half way up the plant, with new green growth at top.

  • Thank you for this information, Theresa. We experienced this with our Riesentraube tomatoes this year. Thank you for the tips!

  • Theresa,
    Do you water your new seedlings? For me, this spring and summer were dry. This is completely foreign to Oregon. I have been all over the map on my watering of the garden. So, in other words, my poor garden has been way out of balance. I have hope and faith that by putting to practice the things you are teaching us, I will find and maintain the proper balance. It is taking some effort to understand how to achieve that proper balance. Thank you for your patience and explanations.

  • Betty, sure sorry to hear about those watermelons. When you give all that room and time (for development) to melons, it’s a real heartbreaker when something goes wrong.

    Mary, the variety in the picture was developed by Gary Ibsen and is sold by him at (When you go to that page, type in Big Beef into the search box and it will go right to Big Beef.) It’s an open pollinated version of the Big Beef hybrid which was originally developed by a company that Monsanto purchased. Since I will not knowingly support Monsanto, I stopped buying the hybrid some years ago and was thrilled to learn that Gary Ibsen had developed an open pollinated version.

    Your tomatoes probably have early blight which is very common. I’ve written about it numerous times. Here’s one of the posts you may want to review:

    The plant in the picture has, in the last 4 days, started to develop all the signs of early blight in one spot. It doesn’t look as pretty as it did 5 days ago, but it will more than likely give me tomatoes until frost. Some plants of this variety that were planted in other spots developed some early blight 5 weeks ago.

    My point is: growing this variety will not prevent early blight because so many factors enter in. It is however, an excellent variety to try.

    Hey Farming Bear,
    Hope the BER on your century old heirloom, Riesentraube, was not lasting.

    Usually when I plant tomato seedlings, I plant, water in the seedling and forget it. If it were extremely dry at least two inches into the soil, I would keep an eye on them and maybe water once more.

    It might help you to review the post
    And review all the detailed information in my book on watering again. (I know you’ve already read it, but sometimes it help to re-read.)

    You’ll get the right balance. Just keep tending your garden and observing. Remember the 3 keys (in the book) and let nature balance the rest for you. If you have other questions just ask. You’ll do great!


  • Hi Theresa,

    Couple of questions

    What do you use to stake your indeterminate tomatoes?
    Do you prune your indeterminate tomatoes?

    Thirdly, I threw away pounds of tomatoes due to BER. This is my second year battling BER. I did put a lot of amendments in the ground when I transplanted my plants out in the spring. I also have been stringing them by pruning to one main vine and my plants were less than 2 feet apart.

    As I began cleaning my garden and throwing away tomato after tomato it occurred to me that I have plants to close together, therefore they are competing for nutrition. Can you please weigh in on that thought.

    Very much appreciated!

  • Hi Ladychef –
    I use tomato stakes (also called tomato ladders) to stake my tomatoes. I use the sturdiest ones you can buy that are about 20% thicker/heavier than the others. I really like them and they last for years and years. You can see a picture at In the search box put the words tomato-stakes-ladders to get to the right page.

    No, I do not prune except for removing the bottom branches when the tomatoes get started. You might want to read my post for more details on that.

    Planting your tomatoes too closely together may or may not be a problem. In my garden, I have plant tomatoes about 2 feet apart. They produced excellent quality fruit. BUT, I don’t plant like that now because I feel they get better air circulation when I plant them with more distance between them.

    You didn’t say what amendments you’re putting in the ground, but as I explained in the post, if you are using various purchased amendments and don’t even know if you need them, you’re wasting money and time. Also, I explained my approach to obtaining good soil in the post.
    You also may want to review my post on soil tests here

    If you have the money to do a quality soil test from a lab that specializes in organic, that might definitely be the way to go.

    When you say you are throwing away tomatoes, I hope that means you are digging them back into your soil to recycle those nutrients they took up when forming; or at the very least, composting them.

    Let me know what you end up doing.

  • Hi Theresa,

    I put egg shells, shrimp shells, chickety doo doo, organic tomato fertilizer and vegetable garden fertilizer in each planting hole hoping not to have BER this year. I strung vines, pruned all 80 something plants then the deer came a grazing. Then I ran to the nursery expert and based on that conversation gave each plant a drink of lime. When just about every plant had BER I got discouraged. We did eat tomatoes but I should be putting up bushels and bushels of tomatoes based on the # of plants I put in the ground. I read your post on pruning and I have decided that this stringing and pruning to one vine is way tooooo much. I didn’t keep up with it so my tomato garden looked like a jungle of rotting fruit for the 2nd year in a row. I refuse to give up on growing tomatoes.

    Soooo next year I’m going to plant @ the most 18 indeterminate and 8-12 determinate. I had very good success with the determinates.
    The majority of the debris is in the compost pile. I’m going to plant a cover crop of winter rye. I can’t rotate the indeterminate location so I have to have build that soil.

    Any suggestions other than what I’ve read on your site and book is most welcome!

  • Before I answer you, Ladychef, can you answer the following questions for me please.

    #1 – How long have you planted tomatoes in this one section?
    #2 – How big is the section?
    #3 – How was the ground initially prepared?
    #4 – How do you prepare it in the spring?
    #5A – Have you ever had a soil test? #5B – (If so, what were the results?)
    #6A – What kind of organic material have you added to the soil? #6B How long have you been doing that?
    #7 – Do you mulch?
    #8A – Do you water? #8B – How do you gauge when to water? #8C- What kind of water do you use? (Rain or municipal?)


  • Theresa,

    You are so sweet to take the time with me! I so appreciate your wisdom.

    #1 – This was my second growing season
    #2 – 35 x 25
    #3 – Last year I did straw bale gardening and I grew everything in straw bales including tomatoes
    #4 – This spring I took that decomposing straw and made beds & rows for everything. In the tomato garden I dug holes with a pole digger down into the red clay 12″ or more then put in all the amendments I mentioned. The straw was at least 3″ thick around the base of each tomato plant. I had very good success everywhere else in my garden with the decomposing straw. My peppers, okra, eggplant and squash did very well as well as the determinate tomatoes.
    #5 – No I have not had a soil test.
    #6A – The decomposing straw and leaves
    #7 – I used the straw from last growing season
    #8 – I was watering until I read tending my garden. I stopped and just depended on the rain. When I did water I used well water.

  • This is very helpful Ladychef. The more I know of your situation, the more I can help.
    I want to answer you in a post. Your situation and what I suggest may be helpful to a lot of people.
    I have a few more questions to make sure I understand exactly what you did. I will send you an email with those as soon as I can.

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