Blossom end rot!

GreenThumbGal_07 · July 9, 2020

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 · July 9, 2020

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 · July 9, 2020

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 · July 9, 2020

Quote:

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 · July 9, 2020

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 · July 9, 2020

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 · July 9, 2020

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 · July 9, 2020

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 · July 9, 2020

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 · July 9, 2020

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 · July 10, 2020

Quote:

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 · July 10, 2020

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 · July 10, 2020

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 · July 10, 2020

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 · July 10, 2020

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.

July 9, 2020	#1
GreenThumbGal_07 Tomatovillian™ Join Date: Feb 2006 Location: Northern California Posts: 300	Blossom end rot! 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.

July 9, 2020	#3
FarmerShawn Tomatovillian™ Join Date: Dec 2011 Location: Vermont Posts: 1,001	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. __________________ "Red meat is NOT bad for you. Now blue-green meat, THAT'S bad for you!" -- Tommy Smothers

July 9, 2020	#7
FarmerShawn Tomatovillian™ Join Date: Dec 2011 Location: Vermont Posts: 1,001	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. __________________ "Red meat is NOT bad for you. Now blue-green meat, THAT'S bad for you!" -- Tommy Smothers

July 9, 2020	#8
PaulF Tomatovillian™ Join Date: Jan 2006 Location: Brownville, Ne Posts: 3,296	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. __________________ there's two things money can't buy; true love and home grown tomatoes.

July 10, 2020	#13
edweather Tomatovillian™ Join Date: Jul 2012 Location: Southeast GA, USDA 9a, HZ9, Sunset Z28 Posts: 396	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. __________________ You'll be surprised what you'll never have to do, if you put it off long enough. Last edited by edweather; July 10, 2020 at 08:36 PM.

July 9, 2020	#2
zipcode Tomatovillian™ Join Date: Jun 2010 Location: Romania/Germany , z 4-6 Posts: 1,582	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).

July 9, 2020	#5
slugworth Tomatovillian™ Join Date: Oct 2014 Location: connecticut,usa Posts: 1,152	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.

July 9, 2020	#9
Koala Doug Tomatovillian™ Join Date: Dec 2017 Location: Detroit Posts: 688	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).

July 9, 2020	#10
JerryHaskins Tomatovillian™ Join Date: Jul 2015 Location: Mississippi Posts: 166	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.

July 10, 2020	#14
biscuitridge Tomatovillian™ Join Date: Jan 2014 Location: washington Posts: 499	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.

July 10, 2020	#15
brownrexx Tomatovillian™ Join Date: Feb 2016 Location: Southeastern PA Posts: 1,420	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.