Every year I grow many tomato plants. I never have trouble getting the plants to grow, they get quite large.

I noticed with some varieties, like big zac or reistomate, I get huge plants but small fruit. I would like to get the fruit much larger for the tomato contest coming up.

I don't cut off suckers, I tried that once and seemed to get almost no fruit and thin stem growth that flops over. I read determinate tomatoes you shouldn't do that, but indeterminate you can, not sure what kind mine are.
There is also a way to prune seedlings but I never learnt how to do this so my plants are tall and thin shape.

Not sure how often to fertilize, I use Jobes tomato and vegetable granular fertilizer.

Lots and lots of sunlight and good rich living soil are the two main things tomatoes need. After that, consistent watering is important.

Do you have a photo of your tomato plants that you could share?

For show tomatoes, start with a large variety indeterminate, plant in good deep soil, in full sun, prune to a single leader, thin the crown set to one or two tomatoes. You will not get a lot of tomatoes but you will get size.

farmerdill said:For show tomatoes, start with a large variety indeterminate, plant in good deep soil, in full sun, prune to a single leader, thin the crown set to one or two tomatoes. You will not get a lot of tomatoes but you will get size.

That seems like the answer I was looking for. They get plenty of sun, water, and rich soil so the pruning and fewer tomatoes should solve the problem.