"Common objections to establishing community gardens include the fear that the garden will attract rodents, vandals and undesirables, become a source of unpleasant odour and noise, deprive locals of parking space and look untidy. All of these objections can be dealt with through design and training.
What cannot be dealt with so easily is the other objection: that community gardens alienate public land and that the herbs, vegetables and fruit they produce are for the exclusive benefit of the few who grow it."Grayson suggests there has been an increase in charges of land alienation and exclusivity (in access to the land as well as the produce) because demand for space and land access in cities is higher than ever.
He draws comparisons between use of public open space for gardening and sports grounds, bowling greens etc. and goes on to give suggestions about making community gardens welcoming to passers-by. Of particular interest is mention of a trend among local governments to grant a non-exclusive license to use the land. The license might state that "the public is free to enter the community garden for purposes compatible with gardening".
This sort of arrangement (if made transparent) alongside a welcoming attitude to visitors, some "gleaning" patches (areas where food can be harvested within reach of passers-by), friendly signage explaining that the food is for those who grow it (like the pic above) and an attractive design can all assist in building a good rapport between gardeners and other users of the open space.
Worth a read.