With peppers if you don't take off the ripe fruit, yes, blossoms are less numerous, but that doesn't happen with tomatoes.

Your Costoluto Genovese may like the heat, but you have two things going against you.

First high sustained heat can cause destruction of the pollen making it non viable, but equally important is high sustained humidity, which causes clumping of pollen which makes it non-productive.

So growingtomatoes where youdo you have kind of a double whammy, if you will, aginst you.

I wrote thispost and then realized you were asking about noblossoms,not lack of fruitset, but I'll leave it here anyway, and no, I have no idea why you aren't getting any blossoms at all. But then I also know that folks in your area usually don't get good growth of plants once the heat and humidity set in.

Carolyn

Thanks. Yes, that's true about peppers, but I've never seen that behavior in tomatoes. Just kind of curious. As to growth of plants, no, that's not true. With the right plants -- peppers, tomatoes, eggplant, okra, when the heat sets in is when the plants grow like crazy. Yes, setting fruit will start to be an issue for tomatoes when it gets very hot. But you don't even have a chance to set fruit if you don't have blossoms. I'm looking at leaves aplenty, but not flowers.

This is not an over-nitrogenation thing, either, BTW. I've just used compost, not chemical fertilizers, and have a garden full of other plants with flowers (as well as these tomato plants loaded with fruit).

I have another thought. I do that from time to time.

Do you see any nice green buds, or buds that swell and then wither and then drop off?

Or not even any buds,which I would find to be unexpected.

Carolyn

No signs of any sorts of stress? Then since you are using organics, I'd try either a good side dressing of fresh compost or a dose of an organic phos supplement. Something fast acting (unlike bone meal) say soft rock phosphate.

Dave

Good point. Nope. No buds at all. It's like the plant just decided to to bother anymore (or for a while). Strange.

I don't know how near you are to me here in western Gillespie county but of the ten varieties I am growing this year only the two most prolific have any blooms at all right now and those have very few.
I am attributing this to the very high amounts of hard rainfall we received in late May. We got over 10 inches in less than two weeks (normal is 4 inches for the entire month). The hard rain along with high wind knocked most of the flowers off my plants and they have not yet recovered. By the time they do recover temperatures should be to high for fruit to set, so what is on the vine now may be about it till it cools off in the fall.

So much for my idea of blossom abortion which can occur b/c when the stigma, the female sexual part,moves up through the style most of the time that stigma is self pollenized by the pollen bearing anthers before the blossom even opens and before the bud even opens. (smile)

Which is why I was considering blossom abortion.

Carolyn

OK, I think I figured it out, after a little research. It turns out that Costolutos are especially needful of leader pruning to ensure flowering and production. Never did any such pruning on my plants this year, because I never noticed a need in previous years. But this years crop is especially heavy.

What this does is concentrate the plant energy into main stems, instead of diluting that energy by spawning suckers.

This is an accepted strategy in indeterminates, but seems to make more of a difference in Costolutos. No pruning, no more flowers. It is suggested to stat doing this weekly when the plants are only one to two feet tall. Mine are almost six!

So I gotta get mysef out there and lay waste to some suckers.

You don't indicate the source of that information but it is very old-school and very controversial info at best as many discussions here will show.

So-called suckers, which are actually lateral branches, do not draw energy out of a tomato plant nor do they dilute it. The leaves on those branches are in fact a source of photosynthetic energy for the plant. And removing suckers from indeterminates may be an accepted strategy for some but not for all by any means - with any indeterminate variety. As Carolyn and others have said here in the past when discussing this debate, it is plant abuse. :)

So if you are going to follow that advice I strongly encourage to you to go slowly and with care.

Dave

I think I have the answer, after some research.

It turns out that Costolutos are pretty demanding of leader trimming. If you don't do that, the blooming stops dead. This is what several seed providers say. When the Costoluo is in full growth mode, it's pumping energy into tomatoes and suckers. None left for flowers.

This is a common strategy for indeterminates, but it seems to be especially important for Costolutos. It is recommended that such leader trimming be done every week, once the plant is a foot or two tall. Mine are six feet tall, and have never been trimmed.

Why didn't I trim them? Well, I had pretty good luck with them in previous years without trimming BUT, the productivity this year is 50% larger than previous years. My plans are loaded with fruit.

So I've got to run outside and pinch some suckers!

An indeterminate's main stem has this growth pattern: 3 compound leaves, then 1 flower truss. The pattern will repeat till frost.

And the indeterminate's lateral branches ("suckers") have the identical growth pattern: 3 compound leaves, then 1 flower truss -- again, repeating until frost. Watch your young plants, and it's easier to see.

I was raised to prune to one stem. The only thing that does is eliminate the vast majority of the plant's fruit.

Sometimes there isn't room to keep every single lateral branch. That's the only reason to remove healthy growth.

It is true that given time (from here to eternity !:D) every single one of those suckers/laterals will/should produce some fruits. But the MOTHER branch and the root system have to baby them and feed them until they get a certain mature stage that can make a NET POSITIVE contribution in terms of production. That is what when it is said " directing energy into suckers". This is especially true about the "Johny come lately" ones where the growing season is 4 to 5 months. Considering that from buds to ripe fruit takes about 50 days alone, then most of those late joiners are not going to yield ripe fruits.

Understandably, there are different schools of gardening on this issue. So then it is the gardener's choice and option to practice what he thinks is right for him. That may or may not be the BEST OPTION but nevertheless it is a personal choice.

I'd like to believe that some late trimming will result in the flowers coming back. We'll see. Again, the plant is LOADED with fruit, and we are currently harvesting. But I want to see flowers and little fruit!

It is true that given time ... every single one of those suckers/laterals will/should produce some fruits. But the MOTHER branch and the root system have to baby them and feed them until they ... can make a NET POSITIVE contribution in terms of production. That is what [it means?] when it is said " directing energy into suckers".

You could just as well argue that the lower part of the main branch has to baby and feed the tip of the main branch. Silly, isn't it?

Apologies for the metaphor, but isn't your dominant hand likely to become larger and stronger if you amputate your non-dominant hand? Yet I don't see a line forming for that elective surgery.

This is especially true about the "Johny come lately" ones where the growing season is 4 to 5 months. Considering that from buds to ripe fruit takes about 50 days alone, then most of those late joiners are not going to yield ripe fruits.

Well, there's the accident factor: dogs breaking branches, deer munching, hail, disease, collapsing ring cages, errant golf balls, hornworms.... It's nice to have more and larger plants when disaster strikes. (Ask me how I know this.)

But perhaps you should keep the younger branches and simply trim their flower trusses beginning 50 days before frost. That way the entire plant would get energy from their leaves. Maybe you could run some tests: average plant fruit weight with and without the trimming. Be sure to use enough plants and variables to qualify as a true scientific test. And don't forget to let us know the results.

Well, it can't be all or nothing. If you trimmed all of the suckers, the plant wouldn't grow. So there must be some established strategy of how many suckers to trim off. This idea, oft repeated, that you have to do this trimming every week, doesn't make a lot of sense unless there is some understanding about how much trimming should be going on every week.

You are right it doesn't have to be all or nothing and no one is saying the choice of what to do isn't yours to make either. Just advocating that it be a well-informed choice, one based on an understanding of the pros and cons when made rather than one made just on something read somewhere.

Think of it this way: some claim all indeterminate tomato plants have to be pruned to a single stem and all suckers removed, some argue that 2 or 3 or 4 stems is best and only suckers beyond that number have to be removed, then some of us argue that none of them have to be removed. Point is they all end up with tomatoes.

The differences in the various approaches is the amount of the tomatoes obtained, the amount and type of support the plant needs, and the stress to plant health ratio that results. You decide how important each of those factors is to you.

But there is always a middle road one can take. Given that it is virtually impossible that this one variety should require aggressive pruning to produce when

(a) it produces just fine when not pruned and

(b) it isn't required for any other indeterminate variety and

(c) the most common cause by far for the lack of blooms is nutrient levels or blossom abortion and not any pruning

one has to question the veracity of the advice you read.

So try removing say 3-4 of the larger lateral branches (suckers) that show no potential fruit development and wait 7-10 days to see what happens. You can also trim back by 1/2 some of the biggest leaf branches. If blooms begin to develop then try removing a couple more suckers and leave the rest.

But if nothing happens try feeding the plant with a phosphorous boost and see what happens.

Either way you'll have your answer without overly stressing the plant by overly aggressively pruning it and losing later production.

Dave

Just a quick followup. The flowers are back. Just now opening, and there are more on the way. I put some compost around the base, but otherwise have not done any soil amendments. I did trim some suckers as well. But the big difference is that the huge load of fruit on them is starting to diminish. Just a few near-red fruit in five plants left.

I'm guessing the answer is that these guys are just smart enough to shut down flowering when they are loaded with fruit. When the fruit is gone, they start back up. Not sure exactly what I do with that info. I suppose I could restrict the number of fruit on the vine, in order to encourage continued flowering. One the other hand, I could just let them go bonkers in fruit production, and then just wait until the fruit has been picked before any more start.

Glad to hear that your plants are flowering again.

I have made observation and distinction between "Branching Out" on the leading branches and "suckers) Growing at the lower nodes. Some tomatoes have a branching out growth habit. Each branche keeps doubling. This growth habit is most prevalent in peppers. Case in point: My mortgage lifter double branched and the each one doubled again. Now it has 4 sturdy branches. You cannot tell which one is main. But any growth initiated at lower nodes are suckers that I remove them.

Here is a picture

I'm with Carolyn on this. Tomatoes cease flowering/fruiting above 90F.

Have you considered temporary shading to keep their temperatures a little lower?

Well, flowers not fruiting is a separate problem from plants not flowering.

As to the former, I'll take my chances. Costalutos are well known to be pretty heat tolerant, and I've had good luck with them in the summer months previously. The fruiting had stopped in May of this year, with high temps in the 80s. But I'm not sure that shading is going to make a big difference. The air temp is what counts.