There used to be a really great thread here on how to grow tomatoes in AZ and what varieties worked best. I don't know if it is still around or if the search will pull it up. But the main point I recall from it was the importance of planting out at the right time - which is very different from much of the rest of the country. It is more of a winter growing season as I recall.

The Arizona Gardening forum here might be able to guide you to the varieties that work best. And researching the so-called "heat tolerant" varieties will help too.

But the bottom line is that with air temps above 95 the pollen in most any variety isn't viable so no fruit set results. Doing things like shading the plants can help some too, even here we have to resort to that.

Dave

Here is a link that might be useful: AZ Gardening discussions about tomatoes

Today I read about two tomatoes that hail from Arizona. Both can be found on Native Seed Search Website. The two varieties are Prescott heirloom, and Nichols Heirloom.

A few days back there was a guy who said he had a terrible time growing tomatoes in Sacramento. So I did a Google search for GW threads where sautesmom/Carla in Sacramento had posted, and gave him a bunch of links where she spoke about tomatoes that did well for her. A couple of those threads were great hot-desert-tomato discussions and today the best one no longer exists, according to GW. *sigh*

Anyway, here's the other great thread:
http://forums.gardenweb.com/forums/load/tomato/msg0716384122262.html

And another that's worth looking at:
http://forums.gardenweb.com/forums/load/tomato/msg0204282810466.html

It's generally said that cherries and grapes do better in extreme heat than larger tomatoes.

A lot of people recommend Porter Dark Cherry (aka Porter's Dark Cherry) for extreme heat; Bonnie Plants grows it, and according to a note on my list, suncitylinda believes Bonnie renamed it -- the original name was Porter (TGS and Sand Hill may still be selling it). [There are a whole lot of different Porter-something-else tomatoes, and there are theories that most of the others are a different second variety.]

Then there are the African tomatoes. Here's Tatiana's list:
http://t.tatianastomatobase.com:88/wiki/Category:African_Tomatoes

However, that list doesn't include others reputed to come from Africa: Heidi (Cameroon) and Wuhib (Ethiopia).

Stupice, Yellow/Red Pear, Tommy Toe, Porter can handle the heat. Those tomatoes will handle 100 degress easily but sustained hot sun and heat will do any of them in. Once the temps reach 100s, they need some shade. If you can manage morning sun and afternoon shade, you might make out.

In my experience, its the hot sun that gets them and not the heat.

Sioux, Super Sioux, Porter (the original, not Porter's Pride), Heidi, and most of the "heat set" varieties such as Sun Leaper, Heat Wave, etc will take the most abuse. You could also try some of the very early tomatoes that will set flowers and mature fruit in less than 2 months. They would set flowers and make a crop before the worst of the heat hits.

Two huge requirements are to use a good mulch such as pine needles or a reflective mulch to help keep the soil cool and be sure to put in irrigation. Regular watering makes a huge difference in a desert climate.

DarJones

There is a newer heat tolerant hybrid out called Phoenix have heard about it in a few places but never seen it except in a Wilhite Catalog.

Thanks to all for the help. I think it's too late to do more experimenting this year, but hopefully next year. I have painted all my SWC's white and I have 15 of them in a dome that I have covered with 50% white shade cloth. So far everything is looking good ....... time will tell.

Thanks again, I really enjoy these forums.

I read a post once on one of the Gardenweb forums by someone in the Arizona desert who planted Fourth of July hybrid for spring harvest, cut it back almost to the ground when the weather got brutal (for tomatoes) and let it re-grow for a fall crop. I think it may have been in afternoon shade. This is a very early little tomato, barely slicing size, on an indeterminate plant. Has some disease resistance.

Fourth of July has tough skin and sometimes splits, but in our climate, it can get very sweet when the weather starts to heat up enough to make many other varieties less-than-wonderful.

I second (third?) the Porter suggestion. I got lots of tomatoes off of one last summer even though Oklahoma had the record hottest July in US history. They're just the
size you want as well.