we are also haveing trouble with the heat here in central florida,so i tried grafting a tomato plant onto an eggplant root stock,they say that the result will be a more heat/disease resistant plant which will be perfect for my hot humid area it might be helpfull for you too.

crappygardener23, that sounds interesting! I have no idea how to do that though. I would love to plant some eggplant this year, I hear they do very well in the heat. I am hoping we can build a raised bed soon. Please post your results, it sounds great!

Mountain Princess might be one to try. It's done quite well for me in the past, and this year is no exception, even after more than two months straight of temps in the high 90's and nights in the mid/high 70's. One of the few plants I still haven't pulled from spring crop because it has continued to set fruit.

I am also rather impressed with Yasenichki Yabuchar (new to me this year), in terms of both apparent heatsetting potential and taste.

Something maybe that I could plant in September and have fruit before the frost? Wondering if I plant a seedling now, or if I should wait till it cools off a bit.

Hopefully someone from AZ will see this thread and chime in, but folks in TX who live in zones 8-9 generally plant out for fall crop anywhere from late July to Sept 1.

I personally prefer a fall crop planting date of Aug 1-15, and my rationale for that date as is follows. This gives the plants a month to a month and a half to get big enough to establish and start blooming. My hope/goal (some yrs are better than others) is that by mid-Sept, temps will break just enough to get some fruitset. I've found through trial and error that putting the plants in earlier doesn't do much good. They just sit there, struggle in the heat, and don't do much. I don't see much point in that.

In a 9b, I suspect you'll have more leeway beyond my general Aug 1-7 suggestion, and might want to go a little later. Since you indicate you usually only get frosts in Jan (I get frosts here in Dec, sometimes even the last wk of Nov), a fall planting date in September might make more sense for you.

Another way to look at it is your avg/estimated first frost date. A general recommendation for fall crop is "do not plant later than 100-110 days or so before first frost date" or words to that effect.

Also, it never hurts to throw a few in containers for fall crop, as this gives you the ability to easily move plants around and protect at night later on when it becomes cool.

Another suggestion: do a google search and see if you can find what (if anything) your county extension service recommends for fall planting dates.

Hope this gives you some ideas.

Here in Vegas, which is just a tiny bit cooler than Phoenix, I've had good luck with Sunmaster, Black Prince, and Lemon Boy. The Lemon Boy has an excellent tangy taste. So does the Black Prince, but is just a touch sweeter and a bit small. The Sunmasters are fine, and produce in higher temps (I have one Sunmaster that has put on two tomatoes with temps consistantly over 105..it was only two, but hey that's more than the others have done since the weather turned hot). For the Fall I am going to try a Hawaiian Tropic variety that has been highly recommended for this area. I have some pics of my tomatoes on my blog linked below.

Here is a link that might be useful: Container Gardening in the Desert

I am a newbie in zone 10 CA, but I have to second the Black Prince nomination. It is our tangiest tomato and they grow really well in hotter climates. Personally I think our most robust tomato this year was Roma, but we've had problems with them. They seem to be frail plants that require attention often. They might do better in AZ.