If you go over to the Growing Tomatoes forum here (linked below) you will find countless discussions about BER, its causes, etc. You'll find, reading through them, that it is primarily a water issue, an inconsistent soil moisture issue, that leads to poor distribution of Ca through the developing fruit and that causes BER.

Some varieties are more prone to developing it and Roma, along with other paste varieties, is one of those. A big reason why Roma isn't a popular variety to grow.

In most cases, IF you can stabilize the soil moisture levels with things like heavy mulch, drip irrigation, etc - anything that prevents episodes of too dry/too wet/ too dry/etc. the plant will out grow it and the later fruit will be fine.

There are many other suggestions discussed there, one being earlier planting in your zone so that the plants have a better developed, more mature root system by this time of year. That makes them more stress tolerant and improves the plant's circulatory system.

But other factors also play a role - the depth of your soil. the pH of your soil, the amount and type of nutrients provided, the manner in which water is delivered (EX: soaker hose vs. sprinkler), the stress from pruning, the frequency of watering (depth vs. frequency), etc. Any of those can contribute to BER. So there is no simple solution (despite some of the far out claims made by some) but rather a compound solution that covers all the factors listed above.

We'd need to know far more specific details about your growing methods to begin to guess which is causing you the most problem. Leaf roll is also indicative of inconsistent water issues so that is where I would start looking for the solution. For example, frequent shallow watering rather than less frequent deep watering creates shallow rooted plants and they are especially prone to BER.

http://forums.gardenweb.com/forums/tomato

Dave

First, just to understand, what type of 'garden lime' did you use?

Are these in the ground with soil? If so, what type of soil... sand, loam, clay, etc...? Raised beds with soil, or a soiless mix? Or perhaps containers with a soiless mix?

When you say that the soil dries out very quickly, how are you determining what dry is? How far down is the soil dry? Are you using your finger, or perhaps just eyeing it?

And, lastly, how much water would you say you're providing each day?

ETA: typing at the same time as Dave.

As weird as this sounds (and it sounds weird) I solved my early BER problem by using a winter snow melt pellet product that is supposed to be eco friendly (more so than NaCl). The snow melt pellets are Calcium Chloride and just a teaspoon full sprinkled around the plant helps with any temporary calcium deficiency your soil may have. Naturally as the tomato plant grows bigger the deeper roots should take care of the uneven moisture/Ca uptake problem.

You'd do well to have a soil test done. BER is a symptom of inadequate calcium uptake, but not necessarily produced by inadequate soil calcium. There are a number of things that interfere with calcium uptake. Overfertilization with potassium and magnesium, for example. Overabundance of soil nitrogen can do it as well.

Blossom End Rot isn't something to get overly worried about, especially at this point in the season. There are a host of stressful things that contribute to it but it will likely go away in a short time if you do nothing different. Just pick and toss the affected fruit and in a few weeks hopefully you will be picking all normal fruit.

I won't deny the correctness of other posts but you probably already know that your cherry fruits aren't affected. You've been watering but heat stress can be enough to cause the problem. Try a shade cloth on the hottest days and avoid adding any additional salt to the soil, including fertilizers.

Thank you for the replies. The PH of the soil is a fairly normal 6.5. I'll post my other parameters tomorrow, but they need to develop for overnight for the test kit I am using.

After seeing some fertilizer burns earlier in the season (about a month ago, was using Fish Emulsion) I have since stopped fertilizing with liquids. But we'll see how much nitrogen, etc. is in the soil after testing.

I water with a sprinkler attachment at the end of my hose at the base of each plant for about 10 seconds every day in the morning. The soil generally feels pretty dry even a few inches below the surface.

This is the Garden Lime:

https://www.walmart.com/ip/Espoma-Organic-Gardening-Lime-Soil-Conditioner-6-75-lbs/33192466?wmlspartner=wlpa&selectedSellerId=0&adid=22222222228023729038&wl0=&wl1=g&wl2=m&wl3=52469752631&wl4=pla-84033166271&wl5=9008561&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=online&wl12=33192466&wl13=&veh=sem

I have been doing some pruning on my Park's Whopper, if that might contribute to any kind of stress.

I know it's too late now, but that may, or may not be the ideal product for correcting calcium deficiencies.

It probably should be stated that home nutrient, and pH, test kits are unfortunately not very reliable. Especially for trying to provide the proper conditions to minimize BER, a professional soil test is the way to go. The most cost effective test is usually available through County Ag. Ext. Agents. They don't do the tests, but they usually have information that can direct you to the best source available. If you don't have a local agent (most places in the U.S. have one, but not all,) then a nearby University Ag. Dept., or a local botanical Garden might be able to help.

The problem with BER is, as described above, Ca deficiency is actually rarely the problem with in-ground growing. The problem is the plant's inability to make use of the Ca already present.

If your soil truly does have a Ca deficiency, and BER is the target, a soil test will give you the ratio of Ca to Mg. This can be important in helping your soil provide available Ca to the plants. Different forms of lime will provide differing levels of Ca and Mg.

If though, your soil truly does have a pH of 6.5 (a very desirable pH for vegetable gardens,) and you do have a Ca deficiency, you might want to go easy on lime, or forego adding it altogether. Instead, you might look to pH neutral products like garden gypsum.

All that said, we come back to the question of whether there truly is a Ca. deficiency. Ca deficiencies are actually quite rare. More often, as discussed above, it's the plant's inability to take up enough Ca for both, the fast growing plant vegetation, and the earliest developing fruit. There is a limit to how much water and nutrients any plant can absorb through its roots. And, just like humans, plants use the nutrients in some places in their structures before others. In humans, it's blood pH levels. Your body will actually absorb Ca from your bones if your diet is not providing enough Ca to keep blood pH in the necessary range.

So, for the growing plant, even with oodles of available Ca in the soil, it may not make it to the earliest developing fruits. Instead of adding Ca, the fix then, is to provide conditions that offer the best opportunity for the plant to absorb as much water and nutrients as possible.

In the seedling stage, you want to learn how to develop feeder roots. Early in the growth cycle, after transplanting especially (before flowers are even present,) water deeply, and infrequently. You want the roots to search deeply for water. This will make a very large and efficient root system for the plant to extract water and nutrients (including Ca) from as much soil area as possible. You want to provide an effective mulch to keep the soil evenly moist. Plants are stressed when soils go from very wet to very dry. Deep roots also help to alleviate this problem.

I hope I didn't leave anything out, and BER can be very frustrating, but remember, even in ideal situations, some varieties are just more prone to the problem.

As many have said, consistent watering is necessary. And deep watering is more helpful than light and frequent watering. In my opinion, watering every other day and for a longer time will allow the soil to be moist further down and give the roots a much more consistent source of moisture. which should help tp diminish the blossom end rot.

"I water with a sprinkler attachment at the end of my hose at the base of each plant for about 10 seconds every day in the morning. "

That is your primary source of the problem. All the other factors mentioned, including pruning, can contribute to the problem secondarily but your method of watering is far from the ideal, not nearly enough, plus far too frequent and way too shallow. It only creates shallow rooted, water dependent, and heavily stressed plants.

Please consider an extensive revamp of your approach to watering the plants.

Dave