Advise you not to move it until the fall if you don't want to lose it. Then what I would do when its moved is to mulch it well with well rotted manure or failing that with compost.
Its quite hard to get all the roots so don't be surprised if you get some coming back in the old place next year.

It is good to divide it up every 5 years or so, incorporate some well-rotted manure, but as Steragram said don't do it till autumn. They like an occasional feed with seaweed too (the bottled sort or a mulch from the beach)

From the beach - great but leave it out in the rain or hose it down to get the salt out first!