Get a sling-shot and give them a pain in the buttocks.

LOL, that's what my husband says. He actually bought a bb pistol and nailed one of the deer in the but, it did not break skin, but it did cause some surprise!

But has anyone tried to use plants to keep deer from their property?

The only thing I have discovered is a large dog or a tall electric fence or there is a Deer and Rabbit spray that works. You need to spray every week or so especially if you have rain. A deer rifle works well but it is slightly illegal!

I don't think the hedge idea will work at all. They will be pushing channels through the hedge as it grows and they will keep these channels open. There are thickets in Florida and Texas that are huge. Thickets that are so dense a human couldn't penetrate even a couple of feet into them. Yet, deer and wild hogs have trails going through them all. I'm talking thickets that are more than 100 ft wide as well.