re-siting rhubarb

Hi
I have a rhubarb plant in a large pot, however, I think the pot is too small and I now wish to re-site it in my allotment. It is now growing beautifully and I'm nervous of moving it and disrupting its roots....so my quandary is, do I move it now OR leave it until the growing season is over and risk it being stunted by the pot size?
any help please

 

Pot grown - no problem.

Give the pot a good soak before taking it out. Dig a lot of compost into its new hole and water well.

 

brilliant, thanks. I shall move it at the weekend x