Posted: 29/05/2014 at 10:22
Hi i got this from RHS i would think moving and dividing would be done at the same time,
Division will guarantee a plant identical to the parent and is the most common method of propagation. It is also good practice to divide established crowns about once every five years if they have become weak or overcrowded. Lift crowns between autumn and early spring (usually in November).
Use a spade to divide the crown into sections each retaining a portion of the rhizome (thickened root) and at least one growing point. Sections from the outer part are better than the centres of old plants. Discard any old or decayed parts of the crown. Replant straight away or wrap in damp sacking until ready to plant.