Effective control of weeds requires all land managers to manage weeds on their own properties and encourage others to do the same. Sources of social capital – trust, networks and norms – can influence the behaviour of land managers as well as whether weed management is done individually or collectively. Yet, social norms are understudied compared to other sources of social capital. The aim of this research was to describe the social norms associated with weed management on rural private property in Victoria, Australia, and the extent to which they facilitate or hinder collective action. Data for this analysis came from semi-structured interviews with 31 landholders and observations of 13 events from two case study areas, focussing on the management of gorse (Ulex europeaus). Sixteen social norms were identified, which can be encapsulated by three themes: good landholders, good neighbours, and social learning. These norms influence landscape preferences, weed management practices, propensity to share knowledge and work with others. In general, good landholder norms discouraged collaborative weed management learning and practices. Some good neighbour norms reinforced the individualism of good landholder norms, while others prioritised the public good. Social learning norms supported landscape scale learning and action on weeds. Many of the social norms described here are applicable beyond weed management and indicate that further research on good landholder, good neighbour and social learning norms and the tensions between them are needed to inform agricultural policies that support collective action.