There are some wonderful precedents for turning public space into gardens. In 2005, Growing Power, in Chicago, partnered with the city to transform 20,000 sq feet of beds in Grant Park that previously contained annuals into a decorative vegetable garden. (I wrote about Erika Allen, who heads the Chicago branch of Growing Power, and the rise of urban agriculture for In These Times.)
Here's a photo of the Chicago gardens:
Gardening advocates are rightly pleased. As Rose Hayden-Smith, a historian and food systems educator at the University of California, told the Washington Post: "I kept having to pinch myself in this meeting, We're not the kind of people who have been invited to Washington, D.C., before. We're the guerrilla gardeners, the pollinator people, the seed savers. It wasn't our usual cast of characters. People were grinning from ear to ear."
--Phoebe Connelly