Dear Dr. Boli: You’re not one of those climate skeptics, are you? —Sincerely, David Bullock.

Dear Sir: Dr. Boli is not entirely sure what a “climate skeptic” is. He has always accepted the USDA Plant Hardiness Zone Map unquestioningly. Do you mean to tell him that there are denialists out there? Dr. Boli is nonplussed. He simply does not know how to process this information. But he begs you not to mention anything to his perennials, for whom the Plant Hardiness Zone Map is a sacred text. There is no sense in provoking violence in the garden.