We prune in the late spring and remove the dead flower heads then so they
do allow some protection against the frost during winter. Doing it then
also allows you to see the new shoots and cut back to good strong ones.

Thanks Bob. My three were planted by Homestead Gardens, in Davidsonville,
which costed an arm and a leg. I was surprised that they are in full strong
sun and am thinking about moving them....and so many other things in my
garden....and trying to save some money but don't want to kill them.