Who knows how to unfreeze the ground?

[DennisAJC]

I'd get an auger and drill evenly spaced holes 2 feet deep( For a 20' x 20', maybe 16 holes from a 6" auger bit.)

Fill with rock salt or de-icing pellets, and flood em with hot water from a hose directly from your hot water tank. That will definitely do the trick and the salt will keep the water from freezing up.

There are other ways, but they're not that enviromentally friendly.