in detroit approximately 40 square miles have been reverted to basically unused green space. in many cities, so-called urban farming may be looked upon by cynics like me as an affectation. here in detroit, it's not. with nature taking back the landscape block by block, the urban farm is really the last line of defense. d-town sits on the western border of detroit. where are we? >> we're in the largest park in the city which is called rouge park. >> did you just come in and start digging or did you have permission to come in? >> we had permission to come in. >> was that difficult? >> it was very difficult. we negotiated with the city for two years.