Guerilla Gardening, like its name suggest, is an illicit act of planting and cultivation of greeneries in neglected urgan areas. Well, mostly that - there is also a little bit of subversion going on, as exemplified by the piece above:
Portland, Oregon, USA:
As she walked past America's oldest Mercedes dealership Sandy could not help but accidentally confuse their three pointed star logo for the similar shaped fork logo of the international peace movement (designed by Gerald Holtom in 1958 for the Campaign For Nuclear Disarmament.) So she decided to turn her imagination into reality by doing some guerrilla gardening Matching the box hedge (Buxus semperviren) she added in an extra row late on Sunday 18 March 2007 which happened to be almost four years since the US invasion of Iraq.
Her intervention remained in front of the car show room for three weeks until a gardener removed it. Sandy found where her bush had been dumped and put it back, where it lasted for another fortnight. Eventually Mercedes had enough of it and cleared it away, and Sandy decided she had made her point. The image ... show the logo before and after the dig.