Abstract: Nathaniel Hawthorne’s description of a New England mansion in The House of the Seven Gables (1851) relies on well-established gothic tropes that ghost certain environmental incidents and characters’ reactions to them. In turn, natural encroachment on human structures seems an otherworldly and unlikely phenomenon. This rhetorical move eases tension in stories where buildings symbolize U.S. success at mastering the landscape but also reveals architecture’s constant vulnerability to outdoor elements. This article examines Hawthorne’s depictions of decay to argue that widespread and resilient fungi, most usually mold, underscore human anxieties about the environment lurking amid portrayals of gothic structures like the famed seven-gabled house. Conditions of rot suggest the impermanence of buildings and, by extension, the limits of conquering the natural world, exhibiting an ecological reality that appears less troubling when represented through ghastly but impossible incidents. In Hawthorne’s novel, the haunting presence of fungal forms in materials, both inside the house and in the surrounding area, suggests failed ambitions and a passing socioeconomic status, so that the story transforms decay into spectral manifestation. An ecogothic reading thus highlights how sometimes unseen biological realities, such as conditions for fungal growth, enhance supernatural and existential horrors while also distracting from concerns about nature’s long-term damaging of human structures like houses. Like the mold it studies, this essay treats the psychology of domestic spaces (a major Hawthornean theme) as permeable by showing that the novel’s gloomy atmosphere, ghostly hauntings, alleged curses, and other fantastical events are enhanced by the presence of a veiled ecological catalyst.