Someone's been eating my hibiscus!

Early this summer I bought two lovely hibiscus bushes, one a yellow, the other a deep pink. As soon as I got them home and put on the back deck, I noticed that the yellow one started missing leaves, and then branches. I have been watching the squirrels cut branches from the maple trees and drag them into their nest boxes for new nesting material, so I figured that they were the ones doing it. Well, they ARE the ones doing it, but they are EATING the hibiscus leaves like spinach. They sit up on the railing of the deck and eat the leaves with wild abandon. Now both plants are denuded and just shells of their formal glory. I was just gonna throw them out, but I figure - ah, what the heck- if they grow new leaves, just more for the squirrels to enjoy. This is a picture of a young squirrel on the railing of my deck- this spring's model. His mom will eat from our fingers and she has within the last week or so had a second litter.