Rhubarb, rhubarb, rhubarb . . .

I have finally got round to digging up my inherited rhubarb. How old does it have to be to have bits 6" across and hollow?!

Seriously I have a choice between some really small but healthy bits, and decent sized bits, but with bits of the hollowed crown linking the roots to the shoots.
Should I trim off the remnants of the crown and plant just the part with the shoots, or just clean them up and stick them in?

Also is it possible to propagate from just the roots? As there are a few bits of broken off but decent size and healthy looking root.

Anything that's still solid and healthy looking can be planted, and most of those bits will yield rhubarb. But any parts that are hollow should but cut away and tossed as they've had a type of hollow rot damage from sheer age and won't yield well. Which is why rhubarb should be dug up and divided every 10-15 years or so and the old, rotted stuff tossed.

Thanks, I was afraid of that. I have now got about a dozen tizzy bits. I think I might as well plant all of them but at much close spacing than normal, and if I'm lucky enough that more than three or four survive, I can always thin them out.

Is there any point in dusting with sulphur to help prevent transfer of the rot? (It 'came with the house' same as the rhubarb )