Earthly & Earthy

Earthly means suggestive of belonging to the earth; ordinary, practical: “I could think of no earthly reason to say no to his request of going to the movies.”
Earthy, on the other hand, means practical and straightforward; open and direct: “People were impressed by the Anna Hazare’s earthy realism.”
It can also mean plain and simple in style or not polite; somewhat rude or crude.

We went to the new restaurant which served earthy, organic foods, because none of us could think of any earthly reason to go to a high priced restaurant.