I don't know anything about the product, sorry. Given the length of time this post has sat at the top of the forum without a response I am responding only to age it away.

I am sorry you didn't get a better response.

Since no experts have weighed in on this I will add my frustrations on ground hogs to the forum. I live on a street that is occupied by about ten of these nuisances this year. The 'moms' had a great year with young. They eat everything in my yard except liriope, canna and yucca. The fresher (more tender) the vegetation, the more likely they will eat it. I have had some success sprinkling cayenne pepper on selected plants. I have to reapply the pepper after rain or wind. I am right on the edge of hiring a trapper, even though it will be very expensive!!!

Ropel is usually used to discourage rodents from chewing. I wouldn't want to spray it on any plants I'd intend to eat from the garden, but I guess you could give it a shot on your shrubs. Sometimes the only solution for a groundhog problem is to trap and remove the animals.

Here is a link that might be useful: Groundhog Control & Removal