You can transplant anytime--however, success increases if you transplant when they are dormant. So, that would usually be about February or early March in a cold year. Take advantage of a warm day in February if you can.
If you must transplant after it has leafed out, dig as large a root ball as possible. Be sure to keep it well watered up until the ground freezes. The first year, you may want to mulch it heavily before winter to protect the roots. (Late November or early December when plants have become dormant and most of leaves have fallen). Pull back mulch in spring before bud growth has started. mh
Thank you very much
for the info on transplanting