Evidence links greenspace exposure with restorative benefits to cognition and well-being, yet nature contact is declining for younger demographics. Although natural settings have been shown to restore the capacity to inhibit distracting stimuli, it remains unknown whether smartphone attention capture disrupts nature contact. Here, we analyzed ~2.5 million observations of logged smartphone use, texting, calling, and environmental exposures for 701 young adults over 2 years. Participants’ weekly smartphone screen-time was over double their green-time. The relationship between greenspace exposure and smartphone activity differed by exposure dose, type, and mobility state. Calling and texting increased during short recreational greenspace visits while all smartphone use declined over the first 3 hr in nature areas, suggesting that nature exposure may support digital impulse inhibition. Those with elevated baseline screen-time or green-time significantly reduced device use in nature, indicating that parts of the biosphere may provide a reprieve from the cybersphere for highly connected youth.