Harvesting mushrooms while maintaining their quality remains a challenging task due to their fast growth rate, uneven developmental posture, and soft, easily damaged characteristics. This study proposes a 3D cultivation medium that enables harvesting by deformation to eliminate the mismatch between harvesting and cultivation. The proposed medium embeds a 3D-printed anisotropic elastic support structure in the covering soil, allowing mushrooms to be generated from the sides and bottom. Furthermore, a mechanism is developed to detach the successfully grown mushrooms by uniaxial contraction of the medium, induced by the out-of-plane pressure generated during free-fall. We also discuss how our method can potentially improve yield compared to conventional flat plate mushroom cultivation.