Tropical fruits Avocado Jaboticaba Banana Kei apple Capulin cherry Miracle fruit Cattley guava Natal plum Ceylon gooseberry Papaya Coffee Pineapple Guava Pitanga Grumichama Pitomba Imbe Citrus fruits Calamondin Grapefruit (dwarf) Key lime Kumquat Lemon Lime Limequat Orange (dwarf) Temperate fruits Apple (dwarf) Blackberry Blueberry Fig Stonefruit (dwarf) Good luck! Here is a link that might be useful: CRFG has a list for you :-)

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.

" I was also wondering if the winter climate here is mild enough to grow peaches" Yes, we are the 6th largest producer of peaches in the USA! Nectarines are peaches, so yes on that too. Are they easy to grow? Hell no, not without spraying. You can grow jujube trees here. You have to have the right cultivars, some are hardy to zone 5 Raintree carries them. Sherwood, Sugar Cane, and Contorted will grow here if you're in Zone 6 like me in South East MI. Some persimmons are hardy in zone 6 too, again Raintree nursery has them. I myself grow cherry, peach, nectarine, juneberry, and pluots. I also have a nectaplum tree. Except for the cherry trees, all are very young trees. I have not had fruit on them yet. I recently expanded to other stone fruits besides cherries. I have experience more with berries. Raspberry, currants, blueberries, honeyberries and the like. On Zones, the garden club rates me at 5b, but what is important is the plant's rating. So a plant rated at zone 6 means if it get's colder than -10 degrees, you need to protect it. In my 56 years here, I never seen it that cold, ever! So do you need to protect plants rated to zone 6? Most likely you never will. We are expecting 11 years of colder weather, so it is possible, but unlikely. Some ways to protect them are watering them continually during the cold spell. Building a huge fire near them, putting the old fashioned large bulb Christmas lights on them and leaving on all night. Spray them with a freeze protectant. Cover with mulch or bubble insulation (for berry plants). This post was edited by Drew51 on Fri, Apr 12, 13 at 0:32

Any chance you can solarize without causing too much trouble? 3" of compost would probably be enough to get started, especially if you can solarize first, and then till in the compost. Top that with 2" of hardwood mulch, and you're golden. Also, start going to Starbucks and ask them to collect the used grounds for you. They'll give it to you free. Sometimes I'm able to get about 40 lbs from a single trip to the store up the street. If there is a composting facility near you, you might be able to get free compost or free mulch. The city of Allen has a free compost program. The only problem is that you might end up with undesirable results. My front yard in those pics is nothing more than Texas clay with 2" of compost and coffee grounds on top, with 1.5" of mulch on top of that. Also be careful along your foundation. Typically you want to maintain the mulch line at or below 3" from the top of the foundation to prevent termites. I tend to go a little higher - 1.5-2" from the top of the foundation, but our entire property has a 10 year termite warranty. Here is a link that might be useful: Solarize your grass