We have been growing tomatoes for years and over the last few years have had trouble with them dying off after planting from the bottom up. It seems to be a bug that crawls into the stem. Leaves die off at the bottom at the beginning then further up as the season progresses. Plant eventually dies.
This could be insect or a fungus issue. If you are having this same issue and are planting in the same location you may have a soil issue.
Crop rotation is recommended to help avoid these issues.
I'm listing a few articles that may help you pinpoint the issues and help you have better results in your next growing season.
https://www.gardeningknowhow.com/edible/vegetables/tomato/tips-for-growing-tomatoes.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-plant-problems.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-blight.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/wilting-tomato-plants.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-diseases.htm
I have noticed on my tomato plants, particularly on "Money Maker," black marks or stains on and in the branches. Nearby stems which have this are very hard and brittle and snap rather than break when removed. In addition, I found one tomato on this plant that appeared rotten and removed. I have provided some photographs.
Depending on the zone you're in, tomato plants are starting to die off, so this may not be as much of an issue as you think.
One or two rotten tomatoes is to be expected in any garden, so unless you physically see pests on your plants or ALL of your fruit ends up being rotten, I wouldn't worry too much about that either.
These articles may help you identify exactly what's causing the black marks on the stems:
https://www.gardeningknowhow.com/edible/vegetables/pepper/black-stems-on-pepper-plants.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/blight-infected-tomatoes.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-diseases.htm
I am in New York (Zone 5) and I have had a garden for about 5 years and have not been successful in growing tomatoes and peppers. My first year I did have some tomatoes and a pepper or two but now I cannot get the plants to grow a little before the leaves start to yellow and die off. Within 3 weeks after planting my tomato plants, 3 were basically dead. I went to a garden store and purchased large mature plants to replace the ones that were dead. I sprayed natural insecticide and fungicide but after another three weeks they began to wither and die. Between and around these plants I planted green onions, zucchini and pole string beans that have produced very well (still picking string beans). I am not sure if I have some sort of fungus, blight, disease or soil problem. I am thinking of getting rid of the garden soil and replacing it. How deep should I go? Any thoughts? Joe
I have listed several links to help you pinpoint the issues.
You very well may have a soil born virus or bacteria that has contaminated the garden soil. Crop rotation is important in the vegetable garden.
Solarizing the garden is a way to help prevent some diseases from occurring.
I would recommend a soil test. This will take the guess work out of what your soil may be missing or have to much of such as Nitrogen.
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-diseases.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-plant-problems.htm
https://www.gardeningknowhow.com/edible/vegetables/pepper/pepper-problems.htm
https://www.gardeningknowhow.com/garden-how-to/projects/how-to-solarize-garden-beds-to-eliminate-garden-pests-in-the-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
Do they have a blight?
Is it the tomato fruits or the tomato vine and leaves which are drying up?
Check this article for fruit problems:
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/visual-guides/tomato-fruit-problems.aspx
Check these articles for vine and leaf problems:
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-diseases.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-plant-problems.htm
I plan to follow the advice about wetting the soil and covering the garden with plastic to use the sun's rays to heat up the soil, acting like an autoclave to kill the fungus. Is there anything else I should do in the autumn, now that I've removed the dead plants and black plastic mulch?
Clean up any debrese and dispose of.
These articles have more information.
https://www.gardeningknowhow.com/edible/vegetables/tomato/wilting-tomato-plants.htm
https://www.gardeningknowhow.com/garden-how-to/projects/how-to-solarize-garden-beds-to-eliminate-garden-pests-in-the-soil.htm
I've been yielding nice tomatoes all summer in NY. Now it's October and 15 are still on plant but are green for 3 weeks. It's still flowering but will these ever turn red?
You can pick the last of your tomatoes and ripen them indoors.
This article will help you.
What should I do with all of the rotten tomatoes left in my garden?
Yes! This article has more information for you.
https://www.gardeningknowhow.com/composting/ingredients/composting-tomato-plants.htm