I need to install two pressure treated 4x4s in my yard that I plan to hook a cable to as a dog run. This way he can safely chase rabbits from my garden area. The posts are 10' long. My soil is mostly clay. How deep should I dig the post holes for this length post? Also, I plan to fill the holes with sacrete concrete mix. The bags are 80 lb. each at the local hardware store. How many bags will I need for each post? Any other tips or ideas about this installation would be most helpful.
Thank You :) Rich from PA