Half way through January, and we’re deep into hedge-cutting season. But while some gardeners will be wielding their shears in pursuit of the perfectly perpendicular, my hedges get a haircut that is more beehive than flat-top. All because of ecotones.

An ecotone is any area where one habitat elides into another – the point where, say, sea meets shore, or heathland turns to bog. They can be large, or small: in the British landscape, naturalised woodland edges are an easy ecotone to spot, with green growth dropping from tree canopy down through shrubby understorey, via bracken and bramble to open grassland. And they matter because they tend to be richly biodiverse, particularly when the graph of change is undramatic. Such slowly altering levels of light, air movement and water penetration allow the maximum range of species – animal and plant – to thrive, and in a sustainable garden are worth mimicking wherever you can.