Got a yardful of black (NOT English) walnuts, falling off tree at a rental property. They still have the thick green hull. Are they supposed to, and will turn black, or are they falling off prematurely? I just remember my mother's being in black tarry hulls. She cracked them with a hammer on concrete, and is the only one I've known to have the patience to crack and pick out the nutmeat. I've heard of folks running over them with a car, but that sounds like a mess. I guess it just gets the black tarry hull off, right? Or, don't the shells get smushed into the nutmeat?