Plánta is a mobile and desktop application designed to empower communities to take direct, lawful action against coastal erosion. By coordinating local volunteers to plant marram grass—an effective, natural stabiliser of dunes—Plánta enables low-cost, environmentally sustainable coastal protection. In areas where government or council intervention is slow or insufficient, the app provides a crucial tool for grassroots mobilisation. It helps users navigate the complex legal and regulatory landscape while fostering collective responsibility and resilience. Through accessible technology and ecological restoration, Plánta transforms coastal defence into a community-powered movement grounded in both environmental science and local agency.