I used to grow a couple of dozen varieties, many pink and white hybrids unlike any to be found now that I am out of biz.
I grew them where it rained at least 9 months out of the year in flat sandy loam (raise your bed if not coarse soil) barely covered and we were dry for at least 2 months during the summer, usually longer. They need a chilling for the winter, and yes are much more cold hardy than advertised. Cold wet soil is not a problem, but summer watering is usually a no-no, unless you are in the desert. Keep the crowns at or just below soil surface. We dug and planted with a scoop shovel, the roots go out about 3 feet from the crown and radiate outward shallowly. They can have the tips cut off but I sold and shipped with as much roots as possible, nobody came close to my size of crown. Fall planting is best as there are not many places like I was where the outdoor temps and conditions were perfect for storing these until spring. Most spring sold plants are DOA, if not they won't be as vigorous as fall planted. We once left a stack of robustus out in the field all winter and did not find it until we went out in late spring to replant, they were fine. All replanting had to be done in the late spring when it was dry enough to do it including daffodils. There was no time for fall planting and too wet for it all winter.
To move them do it after they have gone dormant in late summer or fall, just remember to start way out from the crown to keep as much of the root mass as possible, try to use a good flat shovel and under cut with that up to the crown, all the way around before trying to lift them to keep from ripping the roots off the crown.
If you get dry crowns soak them in water to make them more pliable, if you are unsure that they are alive soak and place them in moist soil mix and keep cool, wait to see if small roots sprout on the main ones.
You can also plant them within the root systems of nasty, invasive and water sucking trees (like maples) as long as they are on the sunny side and get enough sun. They deal with that kind of competition very well.
