Vertical plant farming (VPF), defined as crop production utilising vertical space through stacking horizontally or in towers, is a promising and relatively novel type of controlled environment agriculture (CEA). The nascent sector has been riddled with complexities in economic viability, labour, and plant science, evidenced by a landscape littered with failed start-ups. No studies have examined lessons learned from vertical plant farms. We analyse the interviews of 20 industry practitioners growing leafy vegetables, microgreens, herbs and edible flowers. We examine the experiences of both profitable farms and shuttered projects and their reasons for closure. Thematic analysis is used to identify lessons learned. The lessons fall under six themes: i) economics, ii) labour, iii) technology, iv) growing, v) strategy, and viii) risk. We explore these themes to provide guidelines for successful VPF projects grounded in the literature. This discourse includes a risk register comprised of all reported risks affecting VPF.