Although we don't have any rhubarb now, a local chum mentioned a 'trick' he learned a few years ago.
At the end of the season, just dig up the crown, soil and all, and chuck it on the garden somewhere.
'Wait until the frost has got to it, then replant it'! (He's a man of few words, so bear with me)!
The result, after replanting the crown, is astonishing apparently, and well worth some consideration as proved by the fact that my rhubarb failed miserably on 'The Patch', even though I did all I could to make it flourish!
Anyone here know about this?