Public sector organisations increasingly innovate through open innovation practices that originated in the private sector. To explain the use of these innovation practices, extant research has focused on enabling conditions at the individual and organisational level, but has paid little attention to extra-organisational factors such as culture. To address this gap, we adopted a field framing perspective to study the use of open innovation practices in the New York City (NYC) administration. We found that actors in NYC equipped different social positions – insider, outsider and interstitial – and used different discursive tactics – reflective frame blending and supplemental frame blending – to enhance the cultural resonance of open innovation practices. We further theorise these findings with a framework on the enabling conditions for the cultural resonance of innovation practices. Our study contributes to innovation studies by unpacking the role of culture for the use of innovation practices and to the framing literature by specifying the role of discursive tactics and social positions for the cultural resonance of new practices.