Methods for generating high-yield, high-purity epicardial cells are described. Wnt/β-catenin signaling is first activated in human cardiac progenitor cells, by, for example, inhibiting Gsk-3 to induce differentiation into epicardial cells. Methods for long-term in vitro maintenance of human cardiac progenitor cell-derived epicardial cells and method comprising chemically defined, xeno-free, and albumin-free culture conditions are also provided.