Are you using a high nitrogen plant food? Do the plants get full sun? Did you wait and plant when the weather was warm? Tomatoes produce lots of foliage if given a fertilizer high in nitrogen. Nitrogen is the first number on a fertilizer label. For veggies this first number should not be higher than the other two numbers. If you fertilize using only manure or compost you may be offering too much nitrogen.  Try using Osmocote Flower and Vegetable slow release next spring. Full sun and only watering when the soil is dry one inch below ground also helps with fruit production. Sometimes fruit fails to set if the blossoms fall off due to cool weather. Depending on where you live planting too soon can cut back on production. The good news is the green tomatoes can still have time to ripen before frost. Just harvest all green fruit before your first frost date and they will turn red indoors if stored in a dry spot with good air circulation. They do not need to be on a windowsill and ripen best if they are not touching one another. Of course you can also learn to like fried green tomatoes. Keep growing, Marianne Binetti