To support a sustainable planet, preschools need to engage young children with sustainability education. In the United States of America (USA), nature-based preschool programs are likely to promote environmental science and nature education, given their outdoor curricula, but very little is known about how these programs might also cultivate sustainability education. The purpose of the present study was to investigate nature-based preschool teachers' craft knowledge (Grimmett & MacKinnon, 1992) about sustainability education within curricula as they presently exist. We interviewed 22 early childhood educators and administrators across nine early childhood nature-based education centers in the Northeastern United States. Following Davis' (2010) differentiation of education "in," "about," and "for" the environment, we found that most participants promoted activities "in" the environment, such as children spending time outdoors in the woods. Educators reasoned that they focused on promoting "in-nature" based activities because they believed that caring for and loving nature were foundational to promoting sustainability practices. Also, the educators promoted simple everyday pro-environmental behaviors, such as reusing containers, as they believed such acts lead to lifelong sustainable behaviors. Ultimately, we found that almost all of the teachers who participated in our study "wanted" to include sustainability education within their pedagogical approaches, and they did so by focusing on "every-day sustainability practices," but felt they could not engage in more ethically-driven sustainability practices due to curricular and parental barriers.