The shrubs should be moved in the fall when the plants go dormant. this way, they won't even know they've been moved because their roots were 'asleep' at the time.

As for grasses - same thing, although I have moved mine in spring when they were just coming up. No harm done then. it is said though for the miscanthus that i'd need to move this in early summer. I've not done anything yet with this behemoth of a grass but will try to do something soon since it is getting far too big for it's space.

Was just wondering the same thing myself. Perennials such as catmint and coneflowers too? Should I cut them back first?

(Sorry... don't mean to hijack your thread. Seems silly to start another about the same thing) :-)

let the coneflowers go into dormancy and by then its safe to cut back. Same thing with the catmint. Then dig out the plant complete with a good root ball. Then transplant.

BTW - the shrubs should be dug up with a good root ball. Helps because the roots would be undisturbed