The concept of “Green Care” can increasingly be found in mental health and addictions literature and some Psychiatric/Mental Health Nurses are practicing in facilities that base their approach on some or all of the underpinning theoretical elements of Green Care. However, Green Care is not yet widely considered to be part of mainstream psychiatry. Unearthing and articulating its theoretical underpinnings and clinical applications may further advance its legitimacy. Accordingly, this article identifies four principal theoretical elements of Green Care: Connectedness; Contact with Nature; Benefits of Exercise; and Occupation/Work as Therapeutic, each of which is explored and articulated by drawing on relevant literature.