A shared garden turns private effort into a place strangers can enjoy.

Work done on a shared plot does not stay with the person who did it. Someone weeds and plants and waters, and the result is a bench in the sun that a stranger uses at lunchtime without knowing anyone was ever there. That is the ordinary mechanism by which private effort becomes public good. It depends on people accepting that most of the benefit will be enjoyed by others.

Find a small piece of shared space near you and put an hour into it. And if you enjoy somewhere that is clearly tended, discovering who does it and saying so keeps the arrangement alive.