How hot is it down there in Texas? I'm sure you know that over 90 and you'll start losing blossoms.

No, I did not know that. It's been getting close to 90 with the heat-index.

Uh oh. Is the 90 degrees just something to worry about when the plant is flowering? I always thought tomatoes loved the heat, and we'll be getting 90+ degrees in July and August.

Yes, if you check the tomato forums on this site you'll read about something called "blossom drop". The nutshell explanation of it is simply that the pollen gets tacky at temps above 90(F) and the pollinators can't transport from one bloom to the next when it's not powdery...

That being said, the biggest problem I have with tomato production in the summer is the deer eating the plants...