We have a couple of pole barns to build. I called the rental place to see about digging some post holes for us and they said they won't rent out a Bobcat with an auger as long as the frost is in the ground. There can't be but a couple inches. We will use a spud bar and hand diggers if we have to but that takes a while as it is hard clay we will be digging. Any suggestions as to an easier way?