If all the leaves are dying, no that's not normal at all. Check the top of the plant, in the centre, to see if there's any new leaves coming. If not, check the stems (if they have any yet) to see if they're soggy or rotting anywhere. Unfortunate you planted them last November with such a bad winter to follow - that's the cause of your problems now, though you weren't to know how bad the winter would be. Bear in mind best time to plant these is spring or early September, not as late as November.