Perhaps there was brittleness; if so, I don't know what would have caused it.

However, one factor was certainly that the plant was top-heavy. Look where those fruit are: a good foot or more above the top ring of the "cage." The fruit grew. The branch couldn't stay upright. The weight pulled it down.

I can't say why it snapped rather than simply folded over the top ring of the cage. Perhaps there was brittleness. But given the height of the cage and the height and weight of the fruit, this was, as a friend says, An accident waiting to happen. Inevitable.

Add taller supports for your remaining plants. One way is to add an 8' stake or two per plant (buried 1-2' in the ground) and tie the stems to them. You can also add second cages above the first ones, upside-down, and fasten the cages to each other with 3 zip-ties (cable-ties). Or better yet, buy some CRW and make good, tall cages that will be what you need for the future years. [You can use the current cages for shorter plants or flowers.]

This is still June. Your plants will only grow taller.

Have to agree - the problem is your so-called "cages" combined with the weight of the fruit. You'll find many discussions here about the worthlessness of those 3-ring things and this is one of the many chronic problems associated with them. They simply cannot or will not support a tomato plant with fruit weight on it without a great deal of additional support.

Consider switching to either stakes or Florida weave or full size 5-6' cages made from fencing.

Sorry for your losses. Those fruit showing a bit of color will ripen fine in on the kitchen counter.

Dave

I use 6' tall remesh cages. It really helps with the tall indeterminant varieties. And I try to weave the vines around the cages rather than straight up. Short cages with small wires just don't work well.

Others have suggested your caging, and that might very well be the case. Was the fruit cluster in that first picture above the last ring of your cage?

You can get away with the less expensive/shorter cages, but if you do, add a 6-8' stake driven at least a ft into the ground too (for lg indeterminates) and start tying up to it once plants exceed cage height.

lkngarden

I also think it's your cage-height that was the culprit, maybe along with a lot of moisture taken up by the plant. I've noticed that right after rain, say the next morning, my tomato stems are rigid and "crisp" (what you might call brittle). After a couple of attempts to tie them up then, I realized they're very breakable at this stage, so now I wait until they're more flexible to handle them -- when they aren't so water-crisp. With the weight of your fruit and the short cage, it probably was too much physical stress for the plant to handle.

Your plant will recover and continue growing and producing now, probably by getting bushier with lateral shoots.

Like missingtheobvious says, I don't understand why the branches didn't just cascade over the top of the cage and hang down, because that's the experience of most of us with taller cages. But, it happened, so I guess it's live and learn.

If you have room and want to try an experiment, remove all the fruits from the broken off parts of the plant and see if you can root them. Cut the bottoms of the stems off so you have about 12 inches of top-growth, and then remove all the leaves, blossoms, and suckers except for the growing tip, the leaves at the top. Then put the stripped stem into a container with planting soil and keep it in the shade for ten days or so. When it starts new growth, that means the roots have developed and are taking up nutrients. It's ready to be hardened off and planted at that point. (Many tomatoes are as hardy as weeds!)

Good luck with your maters! With a more comprehensive support, they'll do fine.

What I have learned about tomatoes....is that looking up info on how to grow them is pain staking. Especially, diagnosing them. Pictures of "diseased" tomatoes or nutrient "deficient" tomatoes can be extremely misleading. Here's what helps me:

1. PH of your soil (tomatoes don't mind a little acid)
2. well composted tree bark mulch does wonders....a lot of it in the hole dug 3ft x 3ft. nice and loose.
3. add your beneficial bacteria and rock dust if you want and extra calcium etc if you want. And additional slow release fertilizer for low nutrient soils (which is practically everywhere). tomatoes are heavy feeders. Remember, humans eat a little at a time everyday...so do plants.
4. fertilize and water regularly especially as the plant gets bigger.
5. mulch with leaf compost or straw if you want.
6. make sure you have minerals and vitamins in your soil

I had this happen to my tomatoes in my low organic matter soil in my back yard. I mulch my front yard so my tomatoes do better plus I water well in my front vs my back b/c my back is far from our water hose so I have to bucket carry.

but you should double check and see if it is fertilizer related...salt or bacterial imbalance in the soil.

I am curious as to whether any one else has had problems with brittle plants. Earlier this season we had a storm with strong winds. Most of my plants were just beginning to show a few pea sized fruit and almost all took some minor damage. But one plant, my only black cherry, was severely damaged. All but the main stalk and the largest limbs snapped off like dry twigs. When I saw the damage and examined the plant the impression I came away with was that the plant had been extremely brittle. I am at a loss as to why. The plant has since partly recovered. It has about a dozen fruits on it and it looks a lot like Charlie Browns Christmas tree. It still seems very brittle and doesn't look like it's going to make any more tomatoes. It will be culled and replaced with a Fall planting as soon as the few tomatoes it did make ripen. This was the first plant of this variety that I have grown and I had high hopes for it. Does anyone know if brittleness is characteristic of black cherry or if there is something else going on here, and if so, what can be done about it.

I wish I could help. I planted a Dwarf Rosella Purple in a container over the winter. I have a Labrador with a very waggy tail and she wagged some branches off the plant, but it wasn't until I knocked one off myself that I realized just how brittle that plant had become. It also developed puffy leaves and I realized that it wasn't thriving and tossed it out. I now wonder if it was suffering from a magnesium deficiency. I was growing it in Farford potting soil.

Linda

I have been shoveling my branches into tomato cages and was wondering how pliable they are, I was pushing on young brunches though, the older they get the chunkier they become. I too use tomato cages at the base but then I build PVC trellis with tie threads to tie up brunches as they grow. I garden on community garden so no permanent structures or anything bulky to move around for me.

One of my plants is in a wide CRW cage. Some of the branches I have had to tie to the outer wire with string to help support the weight of the fruit to keep from breaking the branches. Though the plant is a Park's Whopper, and the fruit are getting huge. I have had to do the same thing with a Mr. Stripey plant as well. Due to the heavy weight of the fruit. Though I know if growing that one again I will go with a much larger cage.

You'll find many discussions here about the worthlessness of those 3-ring things and this is one of the many chronic problems associated with them. They simply cannot or will not support a tomato plant with fruit weight on it without a great deal of additional support.
They are certainly not "worthless". I use them (every one I have) for sweet peps with good results. Still use 1 short stake/"cage" to keep them from toppling. For ind toms they are of good function only initially. Some other means of support should be provided unless grower decided to let them sprawl.
Reggie

O' Well. The case is history and irrelevant at this time. Unless somebody is experiencing EXACT the same situation.
BUT
I certainly disagree with putting the blame on cage in this case. The cage did not fail and the plant even had not reached to its top ring but broken right in the middle somewhere.
The bad cage could've become a problem when:

-- It yields and bends, falls over.
-- It is too short for a given plant.

None of those had been the case here. There must had been some other reasons. Probably some insects, or disease that has had weakened the stems OR there had been heavy winds, But anyway , the case is a history, we can learn from it but cannot do anything to change it.

If you have more plants and would like help from the very experienced people here to protect the remaining plants from a similar fate, I would suggest posting pictures of your plants and supports. If there is a situation that would increase the risk of breakage in the remaining plants, they might be able to see it and offer advise.

I agree that this was not caused by the short cages. Every year I have plants that outgrow my 5 foot cages. Rarely ever do the plants snap off limbs. Rather they just bend over and even crimp where it rests on the top rung of the cage. But they rarely snap off.
I think the OP needs to tell us more details... varieties, fertilizer regimes, irrigation, and amount of sunlight. As of now, my vote is something to do with fertilizer and / or the amount of sunlight.