Throughout much of the United States, we find ourselves in drought conditions or flooding from excessive amounts of rain. Both of these can hinder the production of fruit for fig trees. The most usual cause though, is too little sun. If your fig is not getting 6 or more hours of direct sunlight then it will not produce. It will flush out a beautiful canopy but it will not have enough energy to produce and it wont. If this is the case then possibly limb up any near by trees and try to get them more sun. Fig trees will not produce until they are 3 to 5 years old as well. If they are younger than 5 then be patient and wait and you will get fruit.
Have these trees ever produced in the past?
What ever happened to your sweet potatoes and melons?