I live at 5A NY and I often feel that getting fruit can be futile due to late frost. In the last 15 years it seems very common that we have a warm April that encourages bloom followed by a colder May that kills blossoms with hard frosts. It's frustrating. The Adirondacks might be cold enough to avoid this weather phenomena.

I also get the feeling that zone ratings on the trees don't tell the whole story. The trees might be able to survive typical winters for their rated zone, but the fruit buds are usually not as hardy as the tree.

Then there are unusually cold winters, like last winter, that threaten to kill any trees that are on the borderline of survivability.

Were I live is mostly heavy clay and shale rock. It's best to plant on slopes and design drainage to prevent water-logging the clay. I don't know what Adirondacks will be like. I assume more rock mixed with clay, which might help with drainage. The ice age glaciers scraped away all the good soil. They stopped around the NY-PA border. The problem is compounded by water erosion in hilly areas. People living on the hills pay big money to have "topsoil" trucked in from the river bed areas so they can garden. The clay here gets brick hard when it dries out.

I have family that lives in central PA and I am always jealous of their success. The soil quality and the weather are so much better that it seems like whole different world... and they are only a 1.5 hour drive away!

With that said, I think some of stone fruits might be ambitious. Unfortunately, it is usually a process of learning through loss. You don't really know what will work until you try. The specifics of the exact area have a big impact on success and failure. Some varieties are significantly hardier than others, which can make all the difference if you are living on the edge.

The list is too ambitious. I would buy serviceberries, sea berry, and other truly cold tolerant fruits, or restrict myself to Zone 4 varieties. There is a nursery along the St Lawrence in upstate NY that specializes in Zone 4 and lower fruit trees.

Darn, would even the American Persimmon and Illinois Everbearing Mulberry be too ambitious?
I thought maybe even apples and quinces avoid the late frosts by blooming late?

Yeh, i was looking at St Lawrence earlier this week and didn't see anything too exciting.

I do like SeaBerry juice from the Russian supermarkets, maybe i'll take a look at that.

Blueberries will thrive in the Adirondacks, as long as you select varieties that are well adapted to the local climate. However, blueberry shrubs are winter-browsed by both rabbits and deer. Lowbush type blueberry shrubs typically get about 16 to 18 inches high, and the shrub will generally be buried in snow during the winter months, which gives pretty good protection against browsing herbivores.

As I said, it depends on the actual site. You need to find out what the typical winter temperatures are like from people that live in the area. Make sure to factor in elevation if it is on hill and the zone ratings applies more to the lowland area. If it typically gets down to -20F or colder at the site, then you have small list of possibilities to work with.You also need to determine the soil type and drainage situation. That alone could eliminate most varieties of stone fruit.

Pears and apples are typically hardier than stone fruits in cold climates with compact soils, so this may be your best bet. Of the stone fruits, I would first try Japanese plums. They seem to be the hardiest to both cold climate and compact clay soil. In any case, you want to make sure dwarfing rootstocks are as hardy as the tree. That could be were your nursery selection will make a difference. You don't want a nursery that uses rootstocks that are unsuitable for your harsher climate.

I know nothing about persimmons and mulberries.