You can take excellent photos with almost any lens, except a wide angle. I have posted many photos on this forum and you may or may not like them. Here's the process I use:
1. You must determine what you're trying to accomplish. My goal is to photograph the entire bloom in focus. I don't want the foliage in my image. This is entirely a personal preference.
2. I set my camera in aperture priority mode. In this mode you can set your f-stop to what's necessary to blur the background.
3. If you want to be certain that the image of the rose (as opposed to the background) is completely in focus you must position the camera/lens so that is parallel to the flower.
4.I use a high resolution camera and a 40mm fixed lens. I try different apertures, usually f/8 or f/11, to determine the amount background blur I want.
5.The lens I use requires me to get close to the bloom; any "normal" (such as the lens that typically comes with the camera) will do. As has been stated previously, using a zoom lens allows the photographer to stand further away.
6.I crop images to eliminate any extraneous stuff in the background.
