Not heard that one before, Alan. A mature rhubarb plant has a large root and would be difficult to dig up without hurting it. All the rhubarb that I have known has done very well for itself without being dug up and frosted anyway.

Alan
That was in the days when rhubarb was forced, i.e. brought on early with some heat. The crowns were lifted and exposed to frost for two weeks to break dormancy, then they were potted up and 'hurried on' with some heat to produce early tender stems. A clever Victorian trick, using rhubarb forcers. Decomposing compost or manure were used to generate the small amount of heat needed. Do you remember the program Victorian Kitchen Garden? They did it on that. Normally, however, rhubarb can be lifted and divided every 5 or 6 years to keep it healthy and vigorous.

if in the ground the roots will get frosted in a normal winter anyway. I divide mine every 5 yrs.

Hi Thanks for your answers. will dig up and split, not been split for about 20 years. many thanks.