This fall I decided to try some 'cool weather tomatoes': Glacier; Kimberly; Polar Baby; and Oregon Spring Bush. They were all germinated in early Sept and transplanted mid-Oct. A couple of the Oregon Spring's are in containers. So far, so good but we are [so far] having acceptable weather for the garden. These toms are said to 'set fruit in cooler temps'. Now if they would just ripen. I have LOTS of green fruit.

I wonder if the failed spring/summer wild cherry plant was a fluke, and the successful spring/summer plants now in decline could be just reaching the end of their bearing.

My point is that all tomatoes should do better in the summer, provided adequate moisture, fertility, etc... but few varieties will do well in the cooler seasons. Also, younger plants will tend to show more vigorous growth, and older plants may begin to decline even when good growing conditions still exist.

As for cool weather tomato varieties: I once grew one called "Cold Set" which I was able to direct-seed even in my short season area. It was like a large cherry tomato with the taste of a regular slicer.

Tomatoes in AZ tend to stop producing in the hottest weather. Small varieties do best (Matt's Wild Cherry didn't stop producing!)

You may have had a problem with watering and the seedlings died.

Your best bet is to try to oversummer your tomatoes for fall production. Use shade cloth and misters to keep your plant alive until the temps break. If you can't do that, then you'll need to grow short maturation varieties, with transplants started inside being set out in early September for mid to late November harvest. Look for maturities less than 60 days.

Once temps start going under 55 at night for long periods of time, your tomato is essentially done maturing. All the tricks -- and I've tried them all -- storing green tomatoes with bananas (for ethylene exposure), pulling plants out and hanging them upside down in a warm garage, will eventually get you some red tomatoes, but the taste will still be immature (pasty).

Thanks for the info AJBB. Should I just pull all the green fruit now and baby the plants through winter?

I have a few nearly ripe cherry-type tomatoes of an unknown variety - came up from the compost. Otherwise, I'm in the same place as MaryMcp ----nursing along varieties she started (thank you very much!) I've thought about building a hothouse with pvc pipe, sheet plastic and duck tape.

Crista, how would you heat it? Will you remove the non-maturing fruit?

Mary, just pull off the fruit and find a good recipe for fried green tomatoes and consider overwintering.

Crista, your "hothouse" is going to need a source of heat at night or it's useless for tomato production, unless the goal is to just keep the plant alive for spring. Your nearly ripe tomatoes will likely continue to ripen if pulled now and stored on your counter. However, anything that's still bright green is a goner.

Haven't figured out a heat source because I don't know how warm it needs to stay. Need to do more reading....get more input (anybody?) about the ambient temperature needed for fruit production to progress as compared to simply keeping the plants alive. Bright green is a goner, huh.

You need a soil temp of 60+ degrees to keep producing fruit.

Most people in the Valley tend to plant tomatoes too late and choose the wrong varieties. They need to be transplated in late August / September to get a crop. It takes at least 2 weeks after transplantion for plants to actually start growing, much less develop fruit.

People forget that we live in a desert. That means extremes of both hot AND cold.

That's it in a nutshell AJBB! I had thought that late Aug/Sep was still too hot for transplants. Mine went in mid-Sep/early Oct, then the cold came in Nov, then it warmed up again, then it frosted. It's a challenge alrighty.

So next year I should start the germination in mid-June for transplanting in Aug/Sep with plenty of shade. Is that about right?

Exactly. Start inside in June/July. Use 50% shade cloth and water 3x a day if possible if it's still hot. Try to get a variety with a low maturation, likely Early Girl. Again, the best way to handle tomatoes here is to get them through the July/August doldrums with aggressive watering/misting/shade rather than transplant.

If you can't start inside, are there any decent local sources that actually have tomato transplants at the right time of year for our climate? That's the problem I always run into -- stuff is never available when it's the right time to plant here, and I just don't have the space indoors to start seeds.

That is correct. According to the University of Arizona Cooperative extension planting guide. Tomatoes should be transplanted in Feb/March and again in July/August. The problem with this year is it was way too hot this past August for any plants. I kept my spring tomatoes alive through the summer by planting them where they get afternoon shad and putting a shade sail over them through the summer. I took it of when it cooled down and have tons of blossoms and some green tomatoes but they are splitting and rotting before they get ripe. Maybe too hot this summer or too much water? Not sure. Check out this guide for planting times in Arizona.

Here is a link that might be useful: Arizona Planting Guide

I'm thinking about trying a dwarf variety indoors with a lamp that. Can bring n for the few months that we can't grow outdoors next winter. There are so many new dwarf varieties that re open pollinated now, not hybrid.
In the meantime, I'm nursing some p,ants through, just trying to keep them alive for early spring tomatoes, like. Do my peppers. Then, will plant my big crop on Feb 15 with another to follow on March 15.
Will start some plants indoors for the fall, which I failed to do last summer.