What plants keep cats away?

I have absolutely no idea, but they are not poisonous to cats. If you want cats to keep away from your garden, there isn't really any way to keep them out. However, you could put a motion-activated noise maker, also used to keep raccoons out of garbage cans. It will make a loud noise, such as an owl hooting and swooping down, a wolf's howl, or a dog barking. If your cat hears these things so close, I'll tell you she'll probably run like h*ll.