Answer: At its most basic, bare rooting is exactly that: simply removing and/or washing the soil from the roots. Often it is done to reduce shipping costs which are calculated by weight or because some states require it to control movement of potential soil-borne disease or insect problems. When done commercially, the plants may be dug in the fall when they are dormant and then carefully stored under very controlled conditions of temperature and humidity -- so that they stay dormant yet healthy during that period. It would be very difficult to do this at home.
Most home gardeners would not need to bare root plants for transplanting because they would be able to dig up a plant complete with rootball and replant immediately. Certainly this is better for the plant because it does not disturb the roots as much! If however in the process you find that the soil falls away from the roots, do not panic. Simply replant at the same depth as they grew before, water well, and they should be fine. Incidentally, it is always a good idea to prepare the new planting spot prior to digging up the plant to be moved. This minimizes the time it is out of the ground, eases replanting and lessens the risk of transplant shock.
Raspberries are pretty tough plants, so you could dig them up in the early spring as soon as the soil can be worked (meaning no longer frozen and not too wet) and either transplant immediately or "heel them in" temporarily until you can prepare their permanent planting spot. As with most plants, you would not have to wait for the average last frost date; in fact, earlier is a much better time to transplant because it allows them time to become reestablished before the heat and stress of summer.
Q&A Library Searching Tips