Both are bringing new forms of horticulture into the heart of the city. And both will depend for their future growth on technological innovation to drive lower costs and hence greater economic viability.
While planning was the key driver to the majority of the 700 green roofs to be found in central London, the roof garden trend is just as much about recognition by developers of the amenity value of quality green spaces.
As Stephen Richards, partner at Gillespies, the landscape architect behind the new Carnary Wharf Crossrail roof garden, notes one of the aims for the garden is to provide an amenity for local residents now that the financial centre has launched a residential sector. Roof gardens will become cheaper and more plentiful, Richards tells us, as engineers keep "pushing the technology".
Further to the east, Agri-tech Catalyst-backed GrowUp Urban Farms has been granted planning permission to build what it claims will be the first commercial scale aquaponic urban farm in a disused warehouse, growing salads and herbs for local sale with the first baby leaves harvested in September.
It follows the launch of Growing Underground which began growing hydroponic LED-lit micro leaves and herbs in a former air-raid shelter in south London last summer. As Stockbridge Technology Centre's science director Martin McPherson notes, those who simply dismiss the potential of such innovation fail to take account of future technological developments which will continue to improve the efficiency of LED lighting, photovoltaic technology, sensor and automation systems.