maintaining the hops plant

[sashurlow]

A couple of my hops plants are getting quite large at the base (the root mass as a whole). How can I maintain the size of the plants and is it necessary? Do I just cut the roots as they spread without digging it up? they are about 4 yr old plants.
Thanks,

 

[B-Hoppy]

You really can't hurt them so just dig a trench around the base of the crown and cut all the rhizomes back to the center and remove them. You'll be able to tell the rhizomes from the roots as they'll have sets of buds about every few inches along the rhizome whereas the roots won't have these structures.

ps: I've posted a few other comments along these lines with some pictures added recently, so check those out.