I would use a cultivating fork and shovel to carefully move bare root once they are dormant, freeing as much root as possible. This way you can plant them in improved soil and it requires less skill and heavy lifting than moving the entire root balls, soil and all. All these species respond well to this method if you are patient and hard-working enough to get most of the roots.

This can be done in fall or early spring, as soon as soil has thawed. If done in fall, trees should be well mulched with something airy, like chopped leaves or leaves mixed with wood chips so soil doesn't heave during winter.

You may want to hire some cheap labor for the day- this is big work in heavy soil.

Good for you.....It would be good exercise, but like swimming upstream in a swift river. If it were possible, postpone the digging until Fall arrives and leaves drop off. It would be very good to deep soak the whole area around each tree so as to change the clay into slushy, gooey, soggy consistency. Dripping, falling-apart wet. With rubber gloves, a sharp shovel a hand pruner, and a garden fork you could slowly try to uncover and clean each root and remove the slushy clay encasing the roots. Cut the roots as far from the trunk as you can. Especially salvage the thin, mossy roots. Gentle handling is very worthwhile. After the "fillet" of tree/roots comes out, you could hose it off to get rid of the remaining soggy clay. If it were possible, soak the entire root structure in a water-holding "vat" made of any kind of frame that could support 6 mil thick plastic sheeting that would make a shallow swimming pool. Let the trees soak for a day or 2 in water that is enhanced with fertilizer. For me, I use a strong dose of Superthrive in the water. Instead of digging a big hole for each tree and covering the tender roots with chunky native soil, I would use several bags of nursery's bagged potting soil to pour on top of the trees to make a mound on top of the undisturbed soil there with the tree staked upright and sitting on top of the soil. Keeping the mound continually moist is necessary so the thin mossy roots don't croak. All of this is greatly improved if done in late Fall. Good luck.

IMO, you don't need to soak roots after digging trees out of moist soil- and the soil should be made quite moist down deep if it's dry at time of digging.

You don't need to remove all the clay form the roots either- most will fall away in the process of freeing the roots and a little clay is fine. It is a standard practice at some nurseries to place some blue clay at the base of wire pots to improve water retention for balled and burlapped trees.

The new site should be ready to slip them into and if you do that right away after digging, you are good to go. If it's a dry day you can always use a hose to keep roots moist as individual trees are moved. Most hair roots will need to regrow anyway, and they are all that aren't resistant to dehydration.

Because you are in a Z5 you should be sure the soil is well insulated with mulch after translplant. You need to look into the best way to prepare it. Usually raised beds, mounds or berms are the ticket in excessively heavy soil. I wouldn't simply make a brand new soil on top of existing one because of a slew of issues- not the least of which is anchorage. Better to create a gradual transition from the amended soil to the existing one than to just bring in all new soil, IMO, but I suppose it can work- if you bring in a cubic yard or two for each tree.

I move many 2-3" caliber fruit trees every year in my nursery operation and the only species I work with that doesn't like bare root transplanting is pears.

I would look the trees over and plan some pruning. You are going to loose some root so should plan to balance it by loosing some foliage.

I assume you have a little latitude in timing. Check the forecast and try to get some mild days after the move.

Thanks to everyone for all of this awesome advice. I am so glad I joined GardenWeb! Thank you!!

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I just planted out a pear tree (a few days ago). It was in a pot, but it was a newer tree, so the roots weren't full filling the pot up yet, so when i went to remove it, i lost some roots. So far its looking just fine, but i icontinue to water it and will probably lose some growth this year, but hopefully it puts out a bunch of new roots and takes off next year.

Get as much of the rootball as you can. I once moved some big arbortvitae in the spring, when they had already started growing...i did it in a heavy rain (very wet spring)..they all made it with flying colors and are huge today (this was many years ago).

Expect some setback, I would not let it fruit next year, especially if the trees are already into bearing age as the roots will need to grow in to support even the weight of the tree. Even if you stake the trees I wouldn't let them fruit so as not to over-stress them.

I usually don't let transplanted trees set fruit first season in new site either, but the issue is how long it takes to return to good vigor. Sometimes transplants take so well that they hardly seemed to have been moved and can bare fruit the first season. Sometimes it might take 2 or 3 seasons if the tree is slow recovering. With clay soil it is more likely to lean on the latter- hard to get the majority of the roots.