An army of self-styled Guerrilla Gardeners is growing across the world, fighting to transform urban wastelands into horticultural havens.

The handbook, On Guerrilla Gardening, by Richard Reynolds, defines the activity as "the illicit cultivation" of someone else’s land.

"Land is a finite resource, and yet areas like this are not being used. That seems crazy to me. And if the authorities want to get in the way of that logic, then we will fight them, but peacefully, showing them what we can achieve with plants. … Scattering seeds is the easiest way to guerrilla gardening. You do not even have to stop moving to do it."