Regents Park and other London royal parks are swapping their flowers for vegetables.
The idea, inspired by US cities, is to give the public an example of the virtues of growing your own fruit and vegetables.
Parks chief executive Colin Buttery said that the idea is to inspire people to invest in a greenhouse so they can try their hand at growing their own.
"The royal parks role is not to have huge areas of land changed, but to act as a demonstration area to show what can be achieved," he said.
"We very much want to support the idea of people growing their food by doing small-scale demonstrations."
St James Park in London set up two "dig for victory" allotments last month to teach schoolchildren about sustainability and recycling.
The allotments were a great success and will be discussed as part of the Growing Food for London conference, which opens today at City Hall.
The event will discuss how best to feed the capital and will play host to environmentalists, park-keepers, food growers and architects.