Digging holes in MD is easy, you can practically do it with a butter knife. Now in what they call dirt here.... think dynamite and pickaxes.
We've got clay here. Since it rains just about all the time, we got wet clay. Every shovelful weighs a frickin' ton.
We got the same thing here in Washington State on the West side of the Cascades. When we had the foundation dug for our house, the guy got off his bull dozer and said "don't ever ask me to come out here and dig again".
It was a joke among neighbors that if you wanted to plant bulbs, a shrub or anything you better get a stick of dynamite. We have boulders the size of cars!