Dogs and gorgeous gardens can co-exist but it isn't always easy- you have to stay two steps ahead of them and think everything through from their viewpoint and their eye level.
I have literally over 250 of these little cages around plants.
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My dogs are 180-200 lbs. and the puppies are very clumsy and the cages do work.
It's just enough of a deterrent to cause them to go around instead of through LOL.
I buy the fencing in bulk and cut to fit.
When the plant reaches a size where it can hold its own I cut the cages off and discard them.

I also think it is important to keep some paths clear.
My beds have room between the fence and the plant farthest back for the dogs to run.
They're gonna do it regardless so I just incorporated that thought into the bed designs.
And everything is dog proofed- even those reindeer there are impaled on steel fence posts driven deep.

As far as your damaged plant, cage it and watch it- that's about all you can do.

Wow, thanks. I do have to put up some fencing to keep him out of the plants... living in brooklyn as I do, I don't have a massive backyard, and the portion with plants can easily be fenced off. My guy is only 25 lbs, but he's a barrel of a French Bulldog AND a puppy. Haha.