Energy-efficient landscaping is a way of designing and decorating your outdoor space so it uses less energy. For example, you could choose plants that don't need a lot of water or fertilizer, which would save energy because you wouldn't have to use as much water or electricity to water or fertilize them. You can also use mulch, which is a material that helps keep moisture in the soil so you can water less often. Finally, you can choose to design your outdoor space with solar lights, or use energy-efficient bulbs in your outdoor lighting. All these things help save energy and energy costs.