For the past two weeks my tomatoes have been blooming like crazy but they are not setting fruit. This is Georgia, but it is not terribly hot. The plants look healthy otherside nad I had plenty of fruit early. This happens to me every year. I grow my tomatoes vertically on a trellis. Fruit collects near the bottom but after mid June my plants bloom but will not set fruit. This does not happen with cherry tomatoes or Romas but just my bigger variety tomatoes. Any ideas? Could it be aphids or some chemical problem?