You can buy a product called Liquid Fence and keep it sprayed with that. Also in times when you are not going to be around, make a cage out of some heave duty wire mesh or chicken wire fencing. Place the cage over the rosebush and stake it down well. I would do both if you have alot of elek activity going on. Some folks I know even have motion activated sprinklers set up so that any movement sets them off, sometimes it works to scare the elk and deer off.
Stan the Roseman