Santa Monica City in Los Angeles County has a number of community gardens but demand for space in them has become so great that residents are forced to wait an average of five years before a plot becomes available.

Several ideas for creating more space, including using school grounds, rooftops and existing parks, were considered but it was felt that the conversion process would be slow and would not create much additional garden space.

The solution that the City officials have come up with is to establish a :"frontyard and backyard registry". Homeowners who have yards which they are unable or unwilling to maintain properly would register them as being available for other residents who would like to do gardening but don’t have the space.

Although the original idea was to enable people to grow vegetables, the registry would also allow homeowners to make space available for gardeners who wanted to grow flowers. 

(Based on sources including the Los Angeles Times.)