Neat idea! The A-frame vertical planter. Take two pallets and nail on a brace (a horizontal piece of wood) in two spots to hold them together. Make sure that the part of the pallet with the fewest planks faces out. You can remove some planks as well.
When all else fails, protect your beds and borders with a low fence. Here, a low picket fence was all that was required to keep this bouncy bruiser at bay. You'll be surprised at how even the most meager fence can be a visual barrier for your dog.