This paper investigates Fletcher Steele’s ideas about nature, and the fitness of gardens, in order to guide and support a reinvigoration of Naumkeag. Its aim is to highlight the protection of ecological resources while preserving aesthetic and historic integrity. This topic is particularly timely as The Trustees of Reservations are in the process of completing an extensive and unprecedented restoration plan, which will be carried out over the next five years. The Trustees have a long history of historic preservation and ecological conservation. This paper explores how these two aspects of their work can be integrated at Naumkeag, with particular attention to the undesigned portions of the site, such as the grasslands’ fen community. It illuminates how Steele’s original conception of the site, his environmental ethic, and his inspired design, can inform the adoption of original sustainable practices in the gardens, guide sensitive plant replacements, and enhance the visitor’s experience and knowledge.