CANNOT MAKE OWNERSHIP CLAIM

As I have mentioned time and time again, there are some people out there who love gardening so much that they'd make use of every available space to create a mini garden.  Take for instance the one shown above.  The owner of the house had put pots of flowers by the road just outside the house.  Even the clothes drying frame is put out there, perhaps to save space.
However I was told by some of my friends that the space outside our house does not belong to us.  It is owned by the town or city council.