We explore the idea of growing biological organs for material production. Resource scarcity and global warming present challenges in balancing sustainability with the demand for highperformance materials. Biological materials bridge this gap with versatile properties, available resources and biodegradability. We describe the spider silk gland to illustrate how organs regulate the self-assembly of hierarchical materials, giving rise to their properties. Similar organ production units can be cultured in vitro and self-organized from pluripotent stem cells, such as hair-bearing organoids. Growing tissues for material production, helps to approach organoid challenges from a new angle, notably the generalization of knowledge acquired from well-studied species to non-model organisms, such as arachnids. We propose a theoretical framework to help transfer information across biological scales and species. Finally, we discuss research opportunities to overcome biological limitations and produce optimal materials, using synthetic biology and biohybrids.