As a good physics teacher will tell you, potential energy depends on position. This can be demonstrated by holding something heavy but previously innocuous – an iron doorstop, for example – above a chattering pupil’s head.
Gardens obey a similar rule of locus. A small patch of parkland has little potential, enough for a chestnut tree perhaps, or some brambles. But moved to the city it becomes a space of almost limitless possibility, holding all the potential to grow a turnip, fatten a pig, mask a stink, boast of taste and make old milkmaids cry for home, not to mention its potential for sex, for drying washing,
