Landscaping brings to mind pictures of broad fields of grass at country clubs, or intricate raised bed flower gardens over manicured lawns. This type of groundskeeping, while making the environment green, can be anything but green in actual practice - it runs the risk of introducing invasive species, requiring extensive irrigation, or fertilizer run-off, and may be intensely power consumptive in the process.
Making a garden or yard that works with nature is called "green landscaping" and it relies on a few basic principles that, by and large, are common sense. If any of this is too hard to do yourself, considering hiring a professional.
Pick Plants Appropriate To Your Area
Your yard and garden are going to be a home for a mini-ecology. Before you pick your perennials, look at plants that are native to your area, or come from similar climates. If you're in a dry climate, consider xerescaping - using desert plants and shrubs - for your plant cover.
While you're at it, check to make sure that the plants you're planting don't have pollen that people are commonly allergic to.
Work With The Land Not Against It
When you start your yard improvement project, the experts say to have the land surveyed properly. It's expensive, but it's worth it - you can learn a lot about the underlying drainage patterns of the stone and soil under your ground cover, and irrigating so that the water flows with the drainage pattern is better than irrigating against that pattern. A similar principle can be used to plant trees and shrubs as wind-breaks against the prevailing breezes in your part of the world.
While you're at it, it also lets you avoid surprises like abandoned septic tanks or ant colonies under the ground, and can help you site trees and shrubs. Speaking of siting trees, always try to use the trees to provide shade to part of your house - this lets your landscaping cut down on your cooling bills in the summer.
Use Technology Appropriately
While your yard project should focus on the plants and the terrain, you're probably going to need to put in some sort of permanent structure, whether it's a raised planter, a retaining wall, or paving stones for a garden path. You can be green in this area too - use recycled concrete and recycled paving stones where you can to cut back on your carbon dioxide load, and get US fired brickworks; in the US, brick-making kilns are fired off of natural gas, rather than using wood or wood waste or oil.
If your project includes a lighting component, you should also look at solar powered lighting systems - these have matured tremendously in the last three years, and are more robust, have better solar panels and use LED bulbs that last forever.