Even Michelle Obama is getting into allotment gardening REUTERS/Jonathan Ernst

A NETWORK of "guerrilla gardens" could spring up across the Square Mile in a bid to give green-starved residents temporary allotments.

Giant grow bags are being lined up for disused sites so that some of the City of London’s 9,000 inhabitants have space to grow fruit and vegetables.

There are only 22 acres of open spaces in the City but the recession has led to the stalling of dozens of developments - leaving free spaces ripe for use.

The grow bags are easily portable and can be relocated when the developers start, or resume, work.

In New York the temporary sites - branded guerrilla gardens because they spring up and then move on silently - have been operating for more than 30 years.

Many inner-London boroughs have waiting lists for allotments for decades - denying many the chance to put their green fingers to use.

Head of open spaces in the City Sue Ireland said: "There are plenty of temporary sites awaiting development and there is no reason why, if carefully done, they could not be turned to other uses.

"We are trying to identify a site on the edge of the Square Mile that would be vacant for between 18 months and two years.

Grow bags are one possibility. They could be butted up together and moved as and when the developers need to start work."

The Commission on Architecture and the Built Environment (Cabe) has estimated that Britain has nearly 74,100 acres of vacant or derelict brown field land and other unused public space that could enhance cities or help communities.

Mayor Boris Johnson has already earmarked more than 2,000 new spaces across the capital for Londoners to grow their own food - most of it unused public space.