Growing stone or pome fruit in the low desert of Arizona is a trip. Citrus on the other hand is easy. You really would have to be careful of your selection to grow stone or pome fruit. 'Tom' of this forum had a script where he could tell you the chilling hours based on the reports from weather underground. Something like that would be absolutely invaluable if not essential, and I don't know why its not more widely available if not built into the higher tone home weather stations. Tucson would not have quite the extreme climate of Phoenix, but on the other hand, it lacks the unbelievably fertile soil of the Salt River Valley. If I still lived there, I would do the basics. Citrus has few pests and no birds, hangs on the tree ripe for weeks or months, and everyone take it for granted. I would get me some high class citrus. In Phoenix, anything other than Key lime does well. I would go for 'Moro' blood orange, for example, or perhaps a 'Bears' lime. (An unbelievably beautiful fruit tree in my opinion. You could grow the lime tree on the front of the house without worrying too much about fruit thieves.) Figs do very well too, and some of the varieties have two crops a year. Figs for some reason have a kind of 'Geeter Lester' image in Arizona. You won't find too many growing in the foothills of Tucson for that reason. Mulberries do well, but until recently it was almost impossible to get a fruiting variety. Don't plant it too close to the house. A Rosemary hedge is a no-brainer too. You have never lived as a gardener until you trimmed the hedge one hot summer morning turned around when you were done and contemplated the $1,000 worth of trimmings you will be throwing into the trash. Pecan trees do well around there, but they are rarely grown. Too big and too much water I suppose. I always wonder why you don't see Pistachios down there, but you don't. Olive trees thrive in Phoenix. they are outlawed by the yahoos because of the pollen. Almost nobody bothers to harvest them, and the occasional Greek or Italian tourist practically faints at the waste. P.S. Don't try and be a hero and dig through the Caliche. Hire a guy with a backhoe, make sure he calls the Bluestake center, and get a real hole. This isn't Kansas, you know.

One way to know if a site is relatively warm (has a longer growing season with fewer killing frosts) is to look for land in mid-fall when you can compare how far along native trees are towards dormancy. Best fruit growing areas are often known in the East and will already have established orchards. People have been growing fruit here for 300 years but you might luck out, I guess, and discover your own tiny "banana belt". As far as productivity- of course you will be able to grow a wider range of varieties in a 6 than a 5 and some would yield more with a longer season- at least over time. But your question really seems to be can you find a Z6 in regions that are predominantly 5. I think it's the leeward (southeast) side of large bodies of water that have moderated temps as in far upstate NY, not far from Buffalo and areas like Lake Geneva. Also along rivers such as the Hudson Valley and running up the Housatonic in CT. Some of the fruit you listed, like cold-hardy figs and Jap persimmons aren't going to work for you, even in a Z6 without protection.

It is so neat to see one of my old posts (under my old name) brought back up again. This reminds me just how much my relationship to growing is constantly evolving.... In the seven years since I started this thread, I have maintained my love of the more exotic tropical and subtropical fruits (I still love visiting Southern California), but at the same time I have done away with the zone denial, and come to terms with my reality. What I know now: ironically, most of the so-called temperate zone fruits are a complete crapshoot due to late springs frosts (though the peaches and cherries are awesome when they produce) jujube is a real winner, along with hybrid mulberry varieties raspberry and grapes are excellent autumn olive does well as a nitrogen-fixing understory shrub with berries as a bonus growing tropical fruits in my sunroom was too much of a pain, mostly due to scale figs and pomegranates are hopeless outside in the ground in my climate, even though they live for many years, they will never produce because they die back to the ground pomegranates (and likely many other tender deciduous fruits) work great in pots if you have a place to overwinter them (I now have a greenhouse!) many, many plants have grown well, but never fruited or the quality of the fruit was not special enough (these include: goji, golden currant, gooseberry, American elder, black raspberry, blackberry, wineberry, black mulberry, dwarf nectarine, etc.). Most of these I have already removed from my gardens a few have failed miserably, including: hardy kiwi, pawpaw, American persimmon (though this one is still under trial) socalnolympia -- I hope you solve the lack of heat problem with your pomegranates -- I think you will probably need a row cover or something similar to allow for late season ripening though. Just be sure to move onto the next experiment if the first does not show promise, because if I knew 7 years ago what I know now, I would be reaping the rewards in a much bigger way!

Thank you everyone for the feedback. If I use the refrigerator method where do I place the seeded pots when ready in December/January? I'll collect seeds in September and cold stratify for 3 months. Seed into pots and put by a window until spring? That's where I'm stuck. I plan on potting 200 seeded pots since I know not all will germinate and male trees will not produce fruit. (Will try to graft male trees later with female scions) I'm not concerned about the seedlings being cold hardy because I'm literally taking seeds from a tree in my backyard.