We recently moved into an older home and now face the challenge of designing a garden that can survive under a very large black walnut tree (not to mention its many brothers and sisters in the neighbouring gardens). I have sourced a number of lists of plants that are tolerant to black walnut and those that are highly susceptible. However, the "tolerant" list is quite limited (e.g. if a plant isn't on the tolerant or susceptible list, what is one to make of it?) Is there is a more exhaustive list available somewhere? Not only are we interested in ideas about plants that can survive the toxins the tree sends out underground, we're also seeking design ideas to counter the overhead barrage that begins in late summer when the walnuts plummet down and render our city-sized back yard almost unuseable for relaxing meals outdoors. (Hard hats aren't very practical). Thanks very much.