Quote Originally Posted by SteveinMN View Post
. . .that tractor is running over deeply-frozen ground. It's not causing any harm at all.
You're right that it shouldn't effect roots or compact the soil or anything, but I'm more concerned about the plants that stick above ground. Things like yucca, the crowns of ferns, and some low crampbark bushes can take a bit of a beating from it, even though the snow offers them some protection. That's not the only reason I usually shovel by hand though - I really do enjoy the challenge!