A wide variety of public and private initiatives aim to support on-farm sustainable development. But these sustainable farming initiatives (SFIs) show considerable variation in their success to do so. To understand success factors and propose appropriate strategies for continuing and expanding SFI’s, we scrutinized the developmental history of Veldleeuwerik (VL), a Dutch SFI, by using concepts from Engeström’s Cultural-Historical Activity Theory (CHAT); i.e. activity system, contradictions, zone of proximal development (ZPD) and expansive learning (Engeström, Y. (1987). Learning by expanding: An activity-theoretical approach to developmental research. Orienta-Konsultit). We found how contradictions between the components of an activity system were dealt with by VL’s participating actors and how they contributed to expansion of its possibilities. By distinguishing eight dimensions in VL’s expansive learning, six potential strategies to expand an SFI’s developmental possibilities could be derived: (i) embed in and align with the agri-food system, (ii) communicate with and towards the broader society, (iii) attract more participants, (iv) guarantee a variety of knowledge exchange on sustainable development, (v) increase the longevity, (vi) guarantee equal positions in decision making. CHAT proved a comprehensive theory to understand change and development at the level of the SFI.