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kawaiineko_gardener

blossom-end rot

Last year I attempted to grow roma tomatoes. They had small brown spots on the end of the fruit (blossom-end); with some of them there were also black spots on the blossom end of the fruit too.

They weren't sunken or soft. Just by doing a bit of research on it, apparently I've found three main causes of blossom-end rot:

*Soil is too cool

*Inconsistent watering interferes with tomato plant's ability to absorb calcium

*Too high levels of potassium and phosporus (I think it's both, but I'm not sure on this) prevents the plant from absorbing calcium.

The thing I'm confused about is the 3rd cause. Fruiting plants (which include tomatoes) need high levels of potassium and phosporus, because this is what helps them set fruit. Yet at the same too high of a level of these plant nutrients can cause blossom end rot? How do you find and apply a balanced dosage of potassium and phosphorus for the plants?

Also I've been told to warm the soil you should mulch. How do you mulch? I know this sounds like a stupid question but I've never done it before. My main question is, if you mulch once (apply it once) does it only have to be done once or is it something that has to be done contiously? If so, how often would you apply the mulch.

Does the mulch just need to be applied on the top layer of the soil?

Comments (14)

  • carolyn137
    13 years ago

    Normally there's plenty of Ca++ in the soil so that it gets to all areas of the fruits. So the problem is not uptake from the roots except if there's no Ca++ in the soil and also if the soil is too acidic in which case Ca++ can remain bound in the soil.

    The major conditions that can induce BER are anything that stresses the plants and the two most common are using too much N or growing in too rich soils and uneven delivery of water, or too hot, too cold, all can play a part.

    Paste tomatoes such as Romas are very susceptible to BER as a group.

    When you talked about P and K I think I covered that when I said that acidic soils bind Ca++ in the soil.

    I've not heard of cool soils being a problem, but that would also be a stress to the plant.

    And the uneven delivery of water would go along with the plants being stressed as well.

    I've never mulched to try to prevent BER b'c there are so many varibles related to stress that don't involve uneven delivery of water.

    Hope that helps.

    Carolyn

    Here is a link that might be useful: BER from the Faq's

  • kawaiineko_gardener
    Original Author
    13 years ago

    Well it says in order to get adequate calcium into the soil you can use dry milk and crushed eggshells. however how much should be added to the soil?

    I do container gardening, normally I mix my fertilizer into the soil when I make my soil mixture (I make my own soil 'recipe' because as stated above, I do container gardening; it requires soilless soil, so normal soil doesn't work)

    Should the eggshells and milk powder be mixed into the soil when I add my fertilizer? Or rather should I just fertilize when the plant starts to set blossoms and fruit, and just skip adding fertilizer into the soil when I make the soil?

    With the application of calcium to the soil, how much should be added? I generally use 30 gallon and 32 gallon containers, and I fill them about three-fourths full, so about 23-1/2 gallons of soil total for the 30 gallon container, and 24 gallons of soil for the 32 gallon container.

    I was thinking of using tomato-tone fertilzer because it's designed specifically for tomatoes. Would this be a good fertilizer to use for tomato plants, and if so, how often should it be applied to the plants, if you're directly applying it to the top layer of soil, rather than mixing it into your soil when you first plant.

    I did use a high-nitrogen fertilizer; also yes cool soil is a problem because where I live has a short growing season; the summers are also milder and cooler compared
    to summers in southern climates. Watering was also inconsistent.

    I also got a late start on planting my seeds, so when they did set fruit, it was when the weather was cooler.

    I also noticed that my fruit wasn't ripening quickly and once the blossoms set and fruit appears isn't it supposed to ripen quickly? If it ripens slowly is this also an indication of insufficient calcium in the soil or the soil
    not absorbing the calcium?

    How can I prevent the problem of the plant not absorbing the calcium in the soil properly. I know one solution is 'don't overfertilize and don't give it a fertilizer too high in nitrogen'. However I can't just not fertilize it either.

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  • taz6122
    13 years ago

    Use a balanced fertilizer as directed or 1/4 strength weekly for containers to avoid all kinds of nutrient problems. A good soaking of just water applied once a month the day before you fertilize will keep most residuals washed away. Make sure your containers drain good so they don't withhold excess water.
    I've never had BER (knock on head) lol.

  • carolyn137
    13 years ago

    It's really best to get a soil test done to see what the Ca++ level is in the soil. As I said above it's very rare that soils don't have enough Ca++ so none needs to be added.

    With container growing it does need to be added b'c you're using artificial soil. A few tbs of pelleted lime as preparation could be used to start with and then a couple of months later do it again.

    Ca++ is not needed for fruit set.

    From the time that fruits are set it can take 30- 50 days until fruits are ripe and it's variety specific. That' why you see the comments about early, mid season and late in the descriptions of tomato varieties or sometimes just DTM's, days to naturity, but those are sheer guesstimates so don't rely on them.

    Most of the variables that cause plants to have stress, the ones I mentioned above, are totally out of your control other than the fertilizer issue or too rich soil issue and ensuring even delivery of water. Where I live water comes out of the sky on a somewhat regular basis, but I don't know the situation where you live.

    Variety X may have BER in one season and the same variety the next season no BER so there's really not much you can do, especially if you want to grow paste varieties.

    I gave up long ago growing paste varieties b'c for the most part most of them do not have great taste and are more susceptible to BEr as well as Early Blight ( A, solani), so I and many others make sauces, etc using the best tasting fruits in the garden and just cooking down the sauce a bit more until it reaches the right consistency,

    But there are a few paste varieties that I think are pretty good, as in fresh eating, so they can make up a good sauce, they might include:

    Heidi
    Mama Leone
    Martino's Roma
    Opalka
    Sarnowski Polish Plum

    ,,, to name a few. To see if any of those interest you, or actually any other variety, please go to Tatiana's Tomato data base, go the alphbetical search method on the home page and click on that and then just look at the page with that variety that usually shows pictures, some reviws, some back ground and seed sources for the variety if there is one,

    Carolyn

    Here is a link that might be useful: Tatiana's Tomato Data Base

  • springlift34
    13 years ago

    I live in Southeast Texas. What kind of soil do you have, and how much direct sunlight do you have on your growing area?

    Down here, we have a great start. I have sandy loam, as well as a rocky sandy/clay loam. As the season goes on, although I have started with good soil, after a heavy rain, followed by a dry spell with heat, my great soil becomes compacted like a rock. The moisture is there,a few inches down, but air becomes the issue. So, I have to mulch.

    Well, maybe I don't but it's usually a good idea.

    Nitrogen depletes from sandy loam quickly from what I read. Also, obtaining even watering seems to me like a job for the willing. The weather.

  • johnnyrazbrix
    13 years ago

    Put epsom salts around your tomatoes when you plant them and your Bossom end rot is gone regardless of what the actual cause is . I suspect that the calcium up take , which in turn provides further nutrients , is upset because of inconsistant moisture . Too much , then not enough , Etc.Cool and damp. I am not a chemist so I cant argue the potassium/ phosphorus over use as a cause.However i use soft rock phosphate , bone meal , fish inards , banana rich compost greensand and wood ashes. The ph is about6.5-6.8.The epsom salts makes the difference. About a half tablespoon per plant in a ring about 3 inches out from the stem.I have not had a BER tomato in years . I have grown on both sand and clay. Same problem , same treatment , same results.I use the same type salts that i soak my feet in Happy Matering johnny

  • taz6122
    13 years ago

    Epsom salts doesn't cure BER johnny. Have you even grown any varieties that are prone to get BER? The use of epsom salts is to prevent magnesium deficiency.

  • johnnyrazbrix
    13 years ago

    Taz
    The only thing I can tell you is that I read about using epsom salts years ago to prevent BER. Growing the same tomatoes using the same culture , same climate , same temps , same humidity , same spacing , etc. , I had BER until i used epsom salts. As i said before I am not a chemist so I cant argue. I do believe I have read that magnesium deficiency is related to calcium deficiency.In any case , if it walks like a duck etc. and it does , I will use it. I advised 3 new gardeners in this area last year to use it and they did not have any BER.I have no vested interest in promoting Epsom salts ( or anything ) . without it I get Ber with it I dont.Happy matering Johnny

  • suddensam
    13 years ago

    My chain of thoughts on blossom end rot is let it be. Take the one or two bad ones off and forget about it. I think you can do more harm then good.
    In my opinion the plant was or is to immature to feed a ripening tomato given whats going on with the plant.
    I have noticed that the only time you see BNR is the first tomatoes on a plant. Most of the time its not worth the wear n tear on the hens butt to try to cure it.
    Plant em if you got em.
    Sam

  • Bets
    13 years ago

    There are a lot of old wives tales about BER (Blossom End Rot) that are propagated by people (and companies) that should know better. They just have not caught up with current research. The information on epsom salts is just as convoluted.

    A Washington State University Puyallup Research and Extension Center document about Epsom salt myths that in part states There are two reports from over 60 years ago on tomato production. When tomatoes are grown on magnesium deficient soil, a foliar application of Epsom salts can relieve magnesium deficiency in tomato plants; no effect on yield was reported. An automatic application of Epsom salts to plants or soils that are not magnesium deficient is a poor management strategy that can injure the plants and contaminate the soil.

    Betsy

  • yumtomatoes
    13 years ago

    I killed some inground roses with epsom salts and will never use them again. A lot of these "homemade" remedies are just BS and/or can injure your plants.

  • springlift34
    13 years ago

    What about the use of small amounts of epsom salts in areas of sandy loam where ideal growing conditions within the soil occur?

    Maybe considering the delayed need for magnesium in a small fashion a foot away in a small trench could have a good effect. Now, this is only for my type of soil,possibly. I am a newcomer too, so do not listen too strongly to my words.

    Most important, what type of soil would you say you have? and also, how much direct sunlight/shade may you have?

  • Bets
    13 years ago

    springlift,

    Before you go scattering epsom salts about or trenching them in, I would seriously recommend that you have a soil test done. You could (as the WSU-P says) contaminate your soil if it does not need the nutrients in epsom salts.

    Betsy

  • johnnyrazbrix
    13 years ago

    I cant speak for anyone else but before I apply anything I have my soil tested.I agree that many home remedies are worthless.I do not rely on word of mouth alone to determine the viability of a product or culture. If I were growing roses and they were not up to standard and someone said " try fish emulsion for example , I wouldnt start dumping fish emulsion. I would try it on one plant and compare.The washington state report above does not state ( as sited above ) that epsom salts will not help BER. It basically says be careful , there may be unwanted side effects. I agree with that.That can be said of many things gardeners use commonly , organic or chemical. Manure is one easy example. Happy matering Johnny