THE DAY BEFORE AN impending January blizzard, the fourth- and fifth- generation growers at the F.W. Battenfeld and Son greenhouses, in Red Hook, were having boiler trouble. The narrow silvery buildings were fringed with giant icicles; inside, Morgan Battenfeld—who apologized that her father, Fred Battenfeld, perhaps the last violet man standing, was focused on the plumbing—showed off a modest, foot-wide bed running along one side of Greenhouse #1, where, impossibly, regal purple violets known as Frey’s Fragrant were flowering. “They’re fragrant when they’re first picked,” Battenfeld explains, “but they lose their scent completely in the cooler.” (Some violet species, in fact, release ketone, a chemical that interferes with the olfactory senses.) Loyal customers return each year to buy nosegays of 30 to 40 stems from the little self-service store on Route 199 in Red Hook.