1 year old lab suddenly diggins and eating trees

Question
Our one year old yellow lab used to rip tree branches down and play with them. We were able to break her habit about 4 months ago.  Now it's back with a vengeance so we had to secure her away from the big cherry laurels.  In response she just dug up three landscape bushes!  She's never done anything like this.  She's very well exercised, gets tons of attention, we're diligent about giving her fresh chew toys on a regular basis.  HELP!!

Answer
Sorry I couldn't be of much help! Good luck!