Rose plant near conifer hedge

hi, I moved to new house in 2014 and i put a rose bed inbetween the lawn area and hedge. the bead is 2 feet wide. recently i started digging in the area around the rose and found fibrous roots. I was wondering if the conifer roots are expanding into the rose bed and sucking out all the nutrients. Would it be a good idea to take a sharp spade and fork it in between the conifer and rose. This way, i might be destroying the roots of both plants but then, if i feed roses then at least conifer wont be sucking the nutrients. Let me know your thoughts.