The digging pit is a good idea if you're dog is not just digging "lay holes" (when it gets super hot out and they dig in the dirt for a moist place to lay). The stake idea is interesting...I wish I had tried that for my border collie cross when he was a pup...but unfortunately we only noticed this year that he had been digging in our raspberry bushes, ferns, etc. and it's too much of a habit by now. He also digs right by the house, which pushes dirt above the foundation and can cause leaking in the basement. Citrus peels and coffee grounds work if they are reapplied often, but I can't eat that many oranges. I have had to lay bricks and rocks in all the places he likes to dig. Before anybody jumps down my throat, he has ample shade available, and also places where digging is "acceptable". I hope you can nip it in the bud before your yard resembles a land mine site: I sure wish I had