A balcony may be small but it’s precious. It’s an effortless escape to the great outdoors; an urban eyrie; our own private piece of sky. Balconies are now considered so vital to the wellbeing of people living in cities in fact, that almost every new flat built in London will soon have to include one (if it doesn’t come with a garden).

Isabelle Palmer’s balcony is one of those high-in-the-sky gardens that, glimpsed from the street, give you the urge to ring on the doorbell and ask if you can explore.

A lack of space can often be an issue for city plots. But urban gardener Keith Reynolds believes that big ideas can still flourish in small places.