Why are my tomato plants not producing?

Use Blossom Set on flowers perhaps?

do you have any blooms on the plants? The flowers are the starting point for the fruit. If you don’t have bees around you you may have to pollinate by hand. Lay off the fertilizer.

How long have they been in the ground? Maybe the flowers aren't ready to appear yet. And what kind of fertilizer are you using? I use fertilizer specifically for tomato plants and then only once about every 3 or 4 weeks. I also water about every 3 weeks with a solution of Epsom salt and water.Not all types of fertilizers are the best for tomatoes--they promote growth but don't encourage blooming. Here is an article I found that you can read: https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-blossoms-no-tomatoes.html

Do not foliar fertilize veggies, you get great green growth, but little to no produce. The only foliar feeding I do is a calcium supplement for the tomatoes. My plants are really getting tall, but the hot steamy weather I think has stopped it from flowering. I only have a few on my grape and sweet 100's so far, but they are usually the first to start producing.

"Leggy " plants are often the result of not being planted deep enough or left to grow in their container boxes too long. When you plant them, plant at least 1/2 to 3/4 of the way up the stem of the plant, this establishes a good root system. I know it sounds painful to do that, but that is what they need. At this point since you have faithfully watered and fertilized, try pinching off the very tops of the plant to remove some of the vertical growth, forcing it to send it's efforts elsewhere making fruit. So far the plant is putting all its energy into growth rather than product.

If you do get blossoms and they stop there, go ahead and pollinate by using a Q-Tip or a clean dry watercolor paintbrush. Go blossom to blossom. Some people actually gently shake the blooms to spread the pollen.

Good luck to you! Wishing you a good harvest.