Not just rocks make pin holes, cockle burrs, cactus, pine needles, etc. I use to lay my hose out on the ground and would buy a new one every few months due to pin holes. Now I use 2 sections, 9ft long of 4 inch, thin wall, pvc sewer pipe cut in half. I have kept the same hose for 5 years.
First lay down the half pipe and then the hose is bungeed in, the hose never touches the ground. The half pipes ride on the rear bumper with bungees holding them in place. Each end sticks out a few inches past the rear bumper and makes a good sight marker when backing :)