How to prevent blossom end rot next year?

nopeda123October 9, 2013

Overall I had a good year, but after a few months started to get BER sometimes. I container grow in pots about 18" across and 18" deep which are big enough to produce a number of fair sized Rutgers tomatoes. I counted 60 at one time on one of the plants. Use Miracle Grow Moisture Control Potting Mix, and water twice each week with water from the lake they grow next to. That method did well, but I'm guessing toward later months the calcium that was in the soil became depleted to the point of getting some BER. Can anyone suggest good ways of providing calcium for later months so it doesn't happen like that again next year?

Thanks for any help!

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jean001a(Portland OR 7b)

Ensure consistent soil moisture.

See the 2nd item in the FAQ

Here is a link that might be useful: BER

    Bookmark   October 9, 2013 at 3:59PM
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digdirt2(6b-7a No.Cent. AR HZ8 Sun-35)

How to prevent it?

First learn what actually causes it and it isn't lack of calcium.

Second, learn what unique factors about container growing causes it to be far more common with them and make it worse. Eliminate those factors. Using too small a container is one of the primary factors. Trying to "schedule" watering rather than actively monitoring plant needs is another.


Here is a link that might be useful: discussions, tips, and techniques for BER

    Bookmark   October 9, 2013 at 5:14PM
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If you continue to use pots, any empty space at the top of the pot could be mulched, to retain moisture.


    Bookmark   October 10, 2013 at 1:59PM
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seysonn(8a WA/HZ 1)

" How to prevent blossom end rot next year?"
Jury still out on this issue.

Does consistent soil moisture prevent BER? How can you define/control that "CONSISTENT" condition ? What is the science behind it?

Does feeding TUMS calcium tabs cure BER? I have to ask my doctor about that.LOL

Is calcium deficiency in soil the cause of BER? The answer seems to be NO. But plant cannot just take the element Ca from soil and enjoy it. The calcium has to be in a certain form , in the right pH environment, in presence of some ions. So this is really a Bio-soil chemistry. Then there exists also a genetic factor. The point where the flower is attache to tomato is like human belly button. it is like an old wound that needs healing and closing up so the bacteria cannot get in and initiate the rot. Sometimes (it seems to me) that dead flower staying on the tomato causes bacterial growth in the presence of moisture. But the primary cause is the genetics of the plant.

    Bookmark   October 11, 2013 at 1:45AM
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While the jury is still out. Why not try a foliar spray with a product that contains both chelated calcium and chelated magnesium. Organic of course! A foliar spray will not change your soils PH or your plants genetics but I have used it and it did work.

    Bookmark   October 12, 2013 at 9:38AM
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carolyn137(z4/5 NY)

Blossom end rot has many causes. But the good news is that it ususally goes away as the plants mature and can better handle the many stresses that can induce it. It used to be thought that BER was due to a lack of calcium but research has shown that plants with BER fruits have plenty of calcium.

Here's a post I wrote about BER and perhaps it will help explain some of the issues:

Blossom End Rot (BER) is one of the most common tomato problems seen in the early part of the season. It is a physiological condition, not a disease caused by a fungus or a bacterium or a virus. Therefore it cannot be treated.

And as I'll explain below, it is very difficult, if not impossible, to
prevent. BER has nothing to do with the blossoms, it refers to the fact that at the end of the tomato opposite the place where the tomato is attached to the stem, called the stem end, is the bottom of the tomato, which is called the blossom end. You often can see remnants of the blossom attached to that end as the tomato forms. At the blossom end one sees a flattened area that looks
leathery and initially brown and then black, as the fruit rots.

BER is said to occur when there is uneven watering, drought, heavy rainfall, excessive nitrogen fertilization, rapid plant growth or root pruning during cultivation, high winds and rapid temperature changes. So lots of conditions have been associated with BER. But the rapid plant growth and nitrogen fertilization are both common to conditions seen early in the season, and indeed, that is when most BER occurs. Then it usually just goes away.

BER occurs because under the conditions just stated, Ca++ moves from the fruit into the vasculature (stems) of the plant. Or, some feel that Ca++ never reaches the fruits because under stress demand for Ca++ exceeds supply.This lowered amount of Ca++ is what causes BER. Excessive rates of transpiration (kind of like sweating in humans) also is involved in Ca++ displacement. Thus, the plant as a whole is NOT Ca++ deficient, the Ca++ has just been displaced.

Many books and magazine articles tell you that by adding Ca++ in the form of lime or eggshells, for instance, that you can prevent BER. That does NOT appear to be true. It was several years ago that I found out that University field trial experiments have so far failed to show that BER can be prevented by addition
of Ca++. I recently e-mailed my friend at Cornell who told me all this two years ago, to again confirm that it was still true, and will update you, if necessary. Peppers and many cole crops are also susceptible to BER and there's quite a bit of literature on BER and Ca++ for those crops also. The results are the same; addition of Ca++ does not prevent BER.

Some data strongly suggests that foliar spraying with Ca++ is of no use because not enough gets to the fruits to do any good. And it's known that the sprays for fruits that are sold are usless. No molecules can get across the fruit epidermis except when the fruits are still small and green. If they did, just what do you think would happen to the fruits when it rained.LOL

Not all varieties of tomatoes get BER. Some never do, others are horrible. That's not surprising since certainly there are slight physiological differences between varieties. After all, almost all garden tomatoes, with the exception of the currant tomatoes are in the same genus and species, Solanum lycopersicum. And we humans are all in the same species, Homo sapiens, var. sapiens...and look how different some of our physiologies are.

So, BER is a physiological condition, cannot be cured, and current
literature data suggests it cannot be prevented. It occurs on some, but not all varieties of tomatoes, is usually seen early in the season and then stops, for most folks. It would be nice to say that you could even out your watering, prevent droughts and heavy rainfalls, ensure even and not rapid growth of plants and not disturb the roots by shallow cultivating. But on a practical basis, I think we all know that's almost impossible. So, BER has never bothered me, I just ignore it, and it goes away with time.

Adding Ca++ to soils that are Ca++ deficient makes sense, but few soils are. And if soils are acidic, Ca++ is not taken up well but addition of Epsom Salts to the soil can aid in Ca++ uptake in such acidic soils.

Many folks add Ca++ and then see that BER disappears. What they fail to realize is that BER is going to go away anyway, as the season progresses. And that's because as the plants get larger they are better able to handle the many stresses that can induce it. So one cannot correlate addition of Ca++ to disappearance of BER. Universities have done so many stidies on this already
because BER is a billion dollar problem in the commercial veggie industry.

Of all the stresses that can induce BER the two that are most under control of the home gardener are fertilization and water delivery.

That is, too much fertilizer causes plants to grow too rapidly and is perhaps one of the major causes of BER developing. Too rich soils do the same thing. Plant growth simply outstrips the ability of Ca++ to get to the fruits.

Mulching to help ensure even delivery of water also can be done and is also one of the two major causes, IMHO, of BER.

BER appears usually on half ripe fruits but also can appear on grass green ones.Lack of Ca++ only occurs at the blossom end of the fruit and it causes tissue destruction which leads to that papery greyish/blackish lesion appearing.Now sometimes that lesion opens up and fungi and bacteria enter and that causes the rotting and also the appearance of fungal growth on and in the lesion.

Just pick off any BER fruits that appear and soon the next fruits to ripen will BERless.

Many books, magazine articles and websites still say to add Ca++ as lime, eggshells, etc, and seem not to be aware of all the research that has been done in the last 20 years. But many books, magazine articles, are now sharing this newer information about addition of Ca++ not being able to either prevent or cure BER except in rare situations of low Ca++ soils or acidic soils.

I suppose it will take another generation for the right information to be present everywhere. And from my own experience i can tell you that there will be folks who will get madder than can be when they read this kind of info becasue they simply believe otherwise. So be it. LOL Addition of modest amounts of Ca++ aren' t harmful, but I feel strongly that folks should know what's going on with past and current rsearch re BER and Ca++.

Hope the above helps.


    Bookmark   October 12, 2013 at 12:31PM
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