How do I get tomato plants to produce healthy tomatoes?

The only time my tomatoes don’t ripen and turn red is when it’s late in the season. Tomatoes need heat to ripen on the vine so maybe you are planting too late or it’s just cooler where you live. Just some ideas, but I hope you have better luck this year.

What zone are you in? Enough sun? Consistent watering? See if these help.

https://www.thespruce.com/tomato-plant-problems-and-how-to-prevent-1402976

https://homeguides.sfgate.com/tomatoes-wilting-rotting-vine-wrong-105419.html

https://commonsensehome.com/tomatoes-not-ripening/

Lots of sun is needed.

It's called Blossom End Rot...... This relatively common garden problem is not a disease, but rather a physiological disorder caused by a calcium imbalance within the plant. It can occur in pepper, squash, cucumber, and melon fruits as well as tomatoes.This common garden “disease” is often brought on by rapid growth from too much fertilizer, high salt levels or drought.

Blossom end rot symptoms occur on both green and ripe fruits and is identified by water-soaked areas that gradually widen and mature into sunken, brown, leathery spots on the bottom end. In many cases, secondary pathogens, which appear as a black, fuzzy-like growth, attack the affected area and cause complete rotting of the fruit. Blossom end rot will not spread from plant to plant.Treatment

Since this plant problem is physiological in nature, fungicides will not work as a control measure. We recommend the following:

1. Choose resistant vegetable varieties whenever possible.
2. Prevent problems by keeping soil evenly moist and by foliar spraying plants with a kelp or calcium solution.
3. Adding high levels of calcium — bone meal, oyster shell or gypsum — to the soil at planting time usually prevents this problem from developing.
4. A layer of mulch (straw, compost, grass ) will help conserve soil moisture during the hot, dry days of July and August.
5. Foliar applications of Liquid Calcium 5% (1-2 Tbsp/ gallon of water) can be used to correct or prevent deficiencies of this essential nutrient. For best results, combine with a natural surfactant to increase adhesion and spray leaves to the point of run-off.
6. Mulching plants will help conserve moisture and provide a more uniform water supply.
7. Avoid using high nitrogen fertilizers which accelerate vegetative growth and reduce the uptake of calcium by plants. A large selection of balanced organic fertilizers are available at Planet Natural.