Other than compost, I throw a bit of Espoma and epsom salt in the planting hole. That is it. I'm not much of a measurer, so I just grab a small handful of each.

A couple handfuls of a long acting tomato fertilizer that contains calcium, like Tomato Tone, Mater Magic, or Miracle Grow Tomato Shake and Feed. Plus a handful of crushed eggshells, even though others insist that won't work.

Also make sure that they are getting evenly watered - not getting dry, then wet, then dry, etc. Not easy to do in Oklahoma, I know.

Nothing. There's all sorts of useless home remedies for putting stuff like TUMS, eggshells, etc. down in planting holes to prevent BER and their use has not been proven to make a difference when universities researched them in controlled studies. The use of Stop-Rot products you spray on the plants also has not been found to be useful via university research.

BER most commonly occurs not because of a lack of calcium in the soil. Rather, it is a physiological issue resulting from uneven watering that impairs how the calcium is distributed and used within the plant itself. Saying BER results from a calcium deficiency in the soil generally is an oversimplification that is not accurate.

What happens is that when the soil is either much too wet or much too dry, the roots cannot function properly and take up calcium from the soil. So, since the survival of the plant is more important than the survival of an individual fruit, the plant's vascular system pulls back the calcium that is already in the fruit in order for the plant to use it. When it pulls back that calcium, that's when the brown to brownish-black lesions appear on the blossom end of the fruit. This will continue to happen sporadically until the issue of uneven watering is fixed and stops interfering in the plants performing their natural function.

If a gardener notices the BER spots on the fruit early enough, and assuming it is irrigation that is the problem and not too much rainfall (which we cannot control), they can correct the watering issue and the BER stops occurring. Sometimes, if you do that early enough, even a fruit that had started to develop BER will sort of recover and still produce a usable fruit---you just have to cut off the part with the lesion on it.

The immaturity of a plant and its vascular system also play a role in the calcium distribution issue because a younger plant sometimes will set almost more fruit than it can support at its present size simply because the plant's vascular system is too small and too immature to support that much fruit. There is no solution for that except for the plant to mature a bit more. This is why BER is often a problem in May or June (or whenever a given plant is setting its first big crop).

So, why do people think the various things they do to prevent BER are working? Generally because of the maturing of the plant, but also because the gardener suddenly becomes more attentive to the plant's needs since they have discovered a problem. Since they notice BER on a youngish plant putting on a heavy fruit load, they remove the BER-damaged fruit, feed and water the plant to help it recover, and the plant makes new growth---not just new fruit but continued growth of the plant both above and below ground. That growth allows it to be able to adequately set and ripen fruit and, perhaps, the gardener is also paying more attention to watering the plant. Truthfully, even if you do nothing more than pull the BER-affected fruit off a plant, you often will not see it develop on future fruit because by the time new fruit have set, the plant and its vascular system are more mature and better able to disribute calcium. However, when people use one of those old wive's tale things like putting egg shells in the planting holes, they credit that instead of even moisture for solving their BER problem. Eggshells, by the way, do not break down quickly enough to provide calcium for the current year's plants.

I have grown tomatoes my whole life, starting out helping my Dad in the 1960s when I was just a kid, and no matter what soil we have grown them in---black gumbo clay, caliche clay improved with organic matter, red clay improved with organic matter, sandy-silty soil, or soil-less mixes in containers, we have only had BER develop over a handful of times in all those decades, and it happened when either heavy or nonexistent rainfall or an inattentive gardener contributed to the problem. The soil is not the problem 99% of the time. The gardener is the problem, or in years with extra-heavy rainfall like 2007 and 2015, the neverending rainfall is the problem. My dad and the other gardeners I knew taught me to pay attention to moisture levels in the soil from the very beginning in order to prevent BER from developing. Being human though, people would rather blame the soil than their own practices.

Just plant your tomato plants in good soil that drains well and keep the soil evenly moist---not too wet because the roots can develop diseases if kept in soggy soil, and not too dry because the plant will be stressed, will develop BER on fruit and will attract all kinds of pests (stressed plants are more attractive to pests than happy plants). Feed periodically with the fertilizer of your choice. I like Tomato-Tone incorporated into the soil at planting, and then use it as a top dressing througout the season, but any product labeled for tomatoes or vegetables is fine. Keep the plants mulched to help hold moisture in the soil, unless you are suffering from a polonged period of heavy rainfall in which case you might want to rake away the mulch to help encourage the soil to dry out. If you see BER developing, evaluate your practices and what you can change, and then do it. If you see it develop during heavy rainfall, there's not much you can do about that, but planting in raised beds at least 6" above grade level improves drainage and helps prevent excessive rainfall from causing BER in the first place. I only grow tomatoes in raised beds or in containers because no matter how much I improve my soil, since it is clay-based it can hold moisture forever if we're having a period of prolonged heavy rainfall.

Hope this helps.

Dawn

can't add much to Dawn's explanation which is point on, but in my experience this is primarily a problem with immature plants. I do throw some bone meal in the hole when planting, but this is really an issue of the plant being unable to take up nutrients rather than a lack of them.

Thanks all! I'll sure watch better this yr.