The increasing pressures on the global eco-system have reached a critical stage. Cities are the center of most pressures on the biosphere and the contribution to unsustainability. Examined critically, the Sustainable Initiatives addressing urban challenges tend to act independently from each other. This situation is called the Silo-Effect, which is the state of isolation of Sustainability Initiatives in the city arena. The Silo-Effect results in a situation where the Initiatives‘ use of time, energy, and resources is not optimal, therefore creating less effective impact towards urban sustainability. The purpose of this research is to suggest solutions to the Silo-Effect by asking the question, What are the components needed to support the cohesion of Sustainable Initiatives across silos in the city? The methodology of grounded theory inspired the data collection and analysis process of thirteen interviews with professionals from the field. Results confirmed the existence of the Silo-Effect and revealed the main components supporting Cohesion Across Silos. Emerging insights include the need to 1) create Supportive Structures that will maximize the abundant social, human, cultural and economic capitals of practitioners, provide a shared space, and support collaboration, coordination and communications efforts between Initiatives, 2) create new models of local governance and funding systems that support cohesion, and 3) focus experimentation on the neighborhood scale to minimize complexity.