The most common reason for not getting any tomatoes has to do with overnight temperatures when blossoms are trying to set fruit. Most tomato plants need overnight temperatures above 55 and under 76. Too hot or too cold, no tomatoes.
When buying your plants, you can often find hybrid plants that are better suited for your local temperatures.
Following are links for hot and cold tolerant plants.
– Tomatoes for cold climates
– Heat tolerant tomato varieties
