Sustainable gardening covers a broad spectrum, but essentially aims to conserve the earth’s resources to ensure they are available for future generations. At the most basic level you might install a water butt or make your own compost rather than buy fertilizer.

When planting you could consider companion plants to keep away pests and diseases, growing food by sowing salad crops among your border flowers or choosing plants that will withstand a changing climate.

Right and below: This is a garden that has been cultivated for over thrity years as a place to grow vegetables and flowers and also to be wildlife-friendly. It contains some of the ancient varieties shown in my illustration for Reader's Digest.

Planning permission will soon be needed for driveways of impermeable materials like tarmac and concrete that cause rainfall run off into storm drainage. Not only is the water lost from the water table but may cause flooding by raising river levels.

Some paving manufacturers, for example Bradstone and Marshals, now supply water storage systems to go under permeable paving surfaces and the stored water can be used on the garden.

If making a new garden, choose materials such as timber from sustainable sources and use local stone where possible rather than concrete products. Living fences from willow, lighter and airier than a hedge, can be used to form screens and archways and do not need concrete foundations.

Combinations of recycled stone and brick make interesting walkways, as with these paths using reclaimed brick, stone and sawn timber.

Traditional techniques are being brought back into use.

Turf, cob and dry stone walls can replace energy consuming block or brick walls.

They also make unusual and decorative structures in the garden.

The gold medal winning Mars garden by Sarah Eberle used rammed earth walls at Chelsea 2007.

There will be a change of emphasis in our gardens in the future and this should make the planet, literally, a greener place.