In spite of a Flemish planning policy that strived the last decennia at conserving the city (or urban areas) and countryside both as functionally and morphologically separable entities and as antipoles, it is observed that due to an unrestrained suburbanisation city and countryside become increasingly interwoven in Flanders. People still reproduce space in these two spatial categories but society and governments are no longer capable in producing this symbolic space in a physical and social way. It is clear that a top-down imposed, uniformising planning discourse is not able to get a grip on present urbanising processes and therefore alternative story-lines are needed. An alternative story line of ‘open space as public space’, points at the societal importance of public space and could be useful in understanding the challenges in present network society. In a context in which almost the entire Flemish space is ‘urban’, open-space-fragments seem to be able to fulfil a role as public space and have to become structuring spatial elements for further urbanisation. Three success factors in (designing) planning the open space seem to have the potential to be a lot more essential to the spatial visioning on open space fragments/rural areas than the current functional delineation of parts of the natural and agricultural structure. At the same time it is clear that multifunctional agriculture (MFA), meeting a broad spectrum of societal demands, is strongly related to the critical success factors for a good functioning of ‘public open space’, not on the reference scale of urban public space but on that of the collective open space at the regional level. A financing construction, which contains three possible alternative financing mechanisms for collective services, has a lot of potential in reinforcing the ‘public open space’. A proactive and offensive role of governments seems crucial in setting up this financing construction.