Blossom end rot!

[GreenThumbGal_07]

Lots of tomatoes this summer, plants are growing fast, and are productive (nights in the mid-50s, daytime mid-70s, no problem with fruit set).
The big problem is blossom end rot. Tomatoes start off looking beautiful then get that ugly brown rotten bottom.
I've read that it is in part due to a calcium deficiency (problem with the plant getting it from the soil). The Espoma Tomato Tone I'd used had calcium in it. I asked at the local garden center and the employee there suggested Espoma Bone Meal 4-12-0 -- and also said I was the second customer to come in that day asking about a cure for blossom end rot. So I applied some yesterday, with plenty of water.
Well, I hope with the good dose of bone meal and watering every evening (these are container plants in a sunny paved area), the next batch of fruits will be picture perfect.

[zipcode]

Calcium, boron and water are the deciding factors. High humidity and low transpiration (hence low water uptake) are a problem. Culling fruit that just started ber is also a problem (fast growth will start in another fruit and it will also get ber).

[FarmerShawn]

Calcium availability or uptake is not the problem. The clue to the real underlying problem is in your first statement: "plants are growing fast." Fast growth causes the plant to divert calcium from the growing fruit to the growing plant. When fast growth slows, BER goes away. Even if you do nothing, add nothing. Often people swear by some remedy they tried, thinking they had solved the problem, when it would have resolved itself if they had done nothing.

[biscuitridge]

Originally Posted by FarmerShawn

Calcium availability or uptake is not the problem. The clue to the real underlying problem is in your first statement: "plants are growing fast." Fast growth causes the plant to divert calcium from the growing fruit to the growing plant. When fast growth slows, BER goes away. Even if you do nothing, add nothing. Often people swear by some remedy they tried, thinking they had solved the problem, when it would have resolved itself if they had done nothing.

I will kindly disagree, if what you are saying is true,then all of my giants would get BER because they grow extremely fast, the problem is in the soil,watering, temps, biology. But adding bonemeal is not going to cure it right away, it may help somewhat ,depending on your soil balance. You are probably having an imbalance of ions in your soil. If your biology is great, it helps when we do the moron (more on) thing,a( little is good but more is better) so I'm suggesting that you focus on your biology instead of NPK.

[slugworth]

Even tomato shape is a factor.
I have had round and plum tomatoes on the same plant
and the plum type had BER.
The round ones were fine.

[GreenThumbGal_07]

Not sure about how the growth rate would affect BER. I've grown in this location before (all container plants) and I don't know if temperature is a factor, or not. The last time I saw BER was on a plum/paste variety (Andes), now all of the tomatoes (both plum and round slicer) have it.
I've never seen BER on a cherry tomato!

[FarmerShawn]

Yes, variety plays a big role. I also never see it on cherries, and rarely on big beefsteaks. But what I explained as the cause is how Dr. Carolyn explained it, and I have seen it substantiated by university studies. I have behaved accordingly in my tomato patch (1000 plants, 350 varieties yearly) and my experience has shown it to be true in my patch - some varieties get it more than others, it always occurs early when plant growth is most vigorous, and always goes away when plant growth slows. And I have never added extra calcium to the soil to combat it. Well, beyond the eggshells in my compost pile. If you are growing in containers, I suppose things may be different. My understanding is that almost no soils are really deficient in calcium, but container mixes may vary.

[PaulF]

Temperature swings, inconsistent watering, growth rates and varieties with tendency to have BER problems or to withstand the problems. Definitely not calcium deficiencies in the soil. It is an uptake and utilization problem. I more agree with Shawn than differ. As growth patterns, temperatures and watering evens out, BER goes away. Like the common cold, no matter what you take for medication, a cold runs it's course then goes away...or not.

[Koala Doug]

GreenThumbGal - What potting mix are you using for your containers? Any additional amendments to the mix?


The Tomato Tone should supply enough calcium to your plants (under a typical feeding schedule), but multiple external factors can interfere with the distribution of sufficient macro/micro-nutrients.

As others have mentioned, it is normally something that goes away as the plant matures a bit more. Though some varieties are more susceptible than others (especially large fruited and paste-type tomatoes).

[JerryHaskins]

Either order on the internet or go to your local garden center (Walmart and Home Depot won't have it) and pick up a bottle of Bonide Rot Stop. A bottle costs about $9.00 but goes a long way.

Mix according to directions (like 2 oz. per gallon of water) and spray or sprinkle it all over the plants. Repeat every week or two.

It will NOT cure any end rot that has started. It will prevent new tomatoes from getting it.

All it is is a calcium deficiency. The Bonide Rot Stop is just calcium in solution.

[GreenThumbGal_07]

Originally Posted by Koala Doug

GreenThumbGal - What potting mix are you using for your containers? Any additional amendments to the mix?


The Tomato Tone should supply enough calcium to your plants (under a typical feeding schedule), but multiple external factors can interfere with the distribution of sufficient macro/micro-nutrients.

As others have mentioned, it is normally something that goes away as the plant matures a bit more. Though some varieties are more susceptible than others (especially large fruited and paste-type tomatoes).

Using SuperSoil, E.B. Stone's Edna's Best Potting Mix, Black Gold Potting Mix (alone or in combination) in a GrowPro 7-gal Grow Bag, in most cases (but Rinaldo has a 15 gal. black plastic pot and man that plant is huge). One plant per pot. No other soil amendments.

I just had a thought: adjusting for ground vs. container, I have never seen a feral tomato plant with BER. Our neighborhood is favorable to "feral" tomato plants that pop up in March from someone's stray salad or sandwich leavings. The heritage might be questionable but the fruit (if the plant hasn't been yanked out as the attractive nuisance it is) is always good-looking.

[GreenThumbGal_07]

Hi Paul, I hope you're right. The weather here has been pretty warm lately in the daytime. Our typical summer weather pattern has been high fog/cool in July and August, with the warmer weather in May/June and September/October. In the past I haven't gotten tomatoes until August, this time I am early. All of the initial clusters of fruit have BER. I don't know if that will still be the case by August or September, but I will keep you posted.

[edweather]

FarmerShawn nailed it. On a side note I use Texas Tomato Food, and haven't had any BER in the past 3 years. It has almost 4% calcium. End Rot has 9% calcium, and looks like pretty good stuff as along as you use it from day one.

[biscuitridge]

I've had it at the cool end of season as well as throughout the whole season, in fact my worst was in the fall,so i don't believe that it is totally weather related.

[brownrexx]

I have had my soil tested by a university lab many times over the years and it has NEVER once been low in calcium although I never add any.

I totally agree with Shawn and Paul. I occasionally get one or two fruits with BER but never more than that. I don't grow paste type because they always get BER in the same soil where calcium has tested high and no other varieties get it.