I hope someone else out there has better news for you. I've grown only one type of tomato that continues to yield after summer temps arrive: cherry.

Thank you! Let's hope someone does have better news.

I had a lot of blossom end rot on Early Girl and never tried them again. Best of luch in finding the perfect tomato!

Thank you! I'm now considering heirlooms too!

I think I found what I'm looking for! After reading some local newspaper articles and blog-posts from my area, I concluded that the Super Fantastic variety is what I'm looking for. If anyone has experiences with the Super Fantastic, I would love to hear them!

Early Girl F1 is great for hot areas with low humidity and cool nights. I don't think I've ever heard of a Texan that was impressed, though. I don't know, but I'd guess you might like Fourth of July F1 more.

Potassium can help increase heat-tolerance somewhat.

You might investigate Amish Paste. It's supposed to be heat-tolerant, prolific and tasty. It's not an F1 hybrid, though. People all over the USA seem to love it. I haven't tried it, myself, but I think I will next year.

Heirlooms and stabilized hybrids can be very prolific, just as F1 hybrids can. Both can also be very not-prolific. However, F1 hybrids sometimes have what is called hybrid vigor, which can lead to them being more productive than either of their parent varieties. So, the odds of hybrids being more productive are increased because of that, but they don't have an exclusive on productivity. For instance, Yellow Pear is a very old heirloom, but it's known to be very prolific. Many hybrid watermelons are only supposed to produce two fruits, however (which isn't really any more than the average for heirlooms).

Also note that more productive than either parent doesn't necessarily mean the plant is productive.

If I were you, I'd want to take a look at what varieties they sell locally. They're probably more likely to do well in your area than just any tomato.

I started a Super Fantastic F1 plant, this year, but I gave it away. The plant looked great, though. I think it's supposed to be similar to Celebrity F1, Champion II F1, Jetsetter F1, and the like. I've grown Celebrity F1. It was nice, but not my favorite for taste. I liked how the fruits grew large so fast, though. I'm growing Champion II F1 and Jetsetter F1, this year, as well as a bunch of other hybrids that may or may not be similar.

The F1 hybrids I grew this year seemed on average to grow to size faster than the others.

As Shule said, Celebrity makes a lot of tomatoes and people who don't know what a good Heirloom taste like won't know the difference. My uncle loves celebrity though. I also grow them and give them to the folks that want my green tomatoes to fry. I'm not wasting my heirlooms for that nasty dish,

Now if you are looking for Open Pollinated, I can recommend some that do well in my heat.

JD Special C Tex, Costoluto Genovese, Mexico, Wild Rose, Cherokee Purple, Daniels, Lithuanian and Hillbilly.

Also, just something to consider. Have you tried growing tomatoes in the fall? I will be sowing my seeds within the next couple of weeks for August transplants. You and I have 2 short seasons for Tomatoes.

we can talk about it further if you like. I like talking Tomatoes. I'm growing a heart I got from Shule this year and they are doing great as well.

I don't understand the concern. I thought tomatoes had to be grown in the heat. Hotter the better as long as you water them enough. They are subtropical plants.

Nope. You have to get them to set fruit before 90 degree days and warm nights set in. The pollin isn't viable during high temps. True they will usually survive and start producing again once the temps drop, but its a balancing act in our climate

Much of the tropics have COOLER summer temps than Texas and the US SW deserts. Even the southern end of the Chihuahua desert is cooler and less extreme than the northern end in Arizona. Most of Mexico has high elevations and are more temperate in their summer temperatures. Same all through most Central america, Ecuador , Venezuela , Peru. By my understanding, it is all about how hot the nighttime temperatures are that impedes fruit setting . Ave 75º at night and fit set gets iffy. Some of the heat resistant ones will set in hotter temps. I have a friend growing tomatoes in Tucson and he is having highs in 104-107 and lows in around 62-65º. He still is getting tomatoes but might be at the end of his season too.

Here in Texas, our tomato season isn't much longer than up north. Why? Because when the heat sets in in July, your tomatoes are DONE. So you plant out as early as possible, and hope the plants can mature before the heat sets in. We had a cool spring this year, so maturation was slow. I usually have tomatoes around the first week in May. This year it was two weeks later. So our tomato season will be shorter this year.

Exactly right about the tropics. To the extent that nighttime lows determine the fecundity of tomatoes, higher altitudes and lower humidity make the nighttime lows lower.

Hotter the better? Nope. Not by a long shot.

I'm curious: Is root knot nematode activity in Texas any different at 90+° F., for those who have nematode problems?

Mexico and Central America are much smaller landmass with shorter distances to the ocean so the heating up of the continental mass that we have here in the US that are not effected by the oceans is more extreme too. We are hotter. One can only look at the temperatures listed on the news to realize that their summers are very different from ours.