Early root growth is critical for plant establishment and survival. We have identified a molecular pathway required for helical root tip movement known as circumnutation. Here we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa HISTIDINE KINASE-1 (HK1), as well as the auxin influx carrier gene OsAUX1, as essential regulators of this process in rice. Robophysical modelling and growth challenge experiments indicate circumnutation is critical for seedling establishment in rocky soil, consistent with the long-standing hypothesis that root circumnutation facilitates growth past obstacles. Thus, the integration of robotics, physics and biology has elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation.