When you look at your landscape, you may ask: Is it aesthetically pleasing? Does it fit my needs? How can I improve it?

But there's another question these days: Is it sustainable?

Sustainable landscaping is a concept that focuses on the resources needed to install and maintain a planted area -- finding and using ways to conserve water, chemicals and natural resources, such as soil and rain. It also seeks to reduce labor.

The principles of sustainable landscaping can vastly reduce costs of maintaining buildings and grounds, so it makes sense for property managers. It also has implications for public spaces, including building grounds, roadways, public parks and recreation areas, schools, hospitals, and business and industrial parks. But, it makes good sense for homeowners too.

Thirty years ago, most home landscaping, whether urban or suburban, consisted of a patch of lawn (a really big patch in some cases), some foundation plantings, a few trees, and perhaps a bed for flowers or vegetables. Plants were chosen for their color when flowering and their easy availability at garden centers. Maintenance included cycles of mowing, fertilizing, spraying, pruning and watering. Short-term climate changes -- a few years of drought, or an exceptionally wet spring -- could have a big impact on how well the plants looked or grew.

That's slowly changing as people learn about native plants, water-efficient landscaping and other environmentally sound practices. We now know that, once established, native plants can endure without synthetic chemicals or fertilizer, or a lot of watering and labor. Ecologists have determined that reducing areas of turf by planting with self-sustaining plants reduces maintenance, increases rainwater retention and rewards the senses with a more varied landscape.

Big as these changes are, they're each a small part of the larger picture that is sustainable landscaping. This style of design takes low maintenance for the garden to another level, by keeping the landscape as close as possible to nature. This process initially takes management to restore the land to a natural condition. It involves the entire property, and considers large issues, such as climate and terrain, and smaller ones, such as plant choices. Here are some of the considerations:

* Climate and microclimate. We're lucky in the mid-Atlantic region to have a relatively moderate climate. We don't have the problem of winter-long snow management like the upper Midwest, and we don't have the water shortage issues of the Southwest. Our landscapes can be managed in conjunction with the climate, rather than in opposition to it. We can arrange landscaping to improve the conditions on our properties.

You can improve a microclimate by planting a windbreak to deflect cold winds or channel welcome breezes. You can plant evergreens on the north side of the house to stop winter winds, and deciduous trees on the south to let low winter sunlight reach windows. You can use the tree canopy to create shade. Improving soil and using carefully selected plants can also make your immediate environment less susceptible to weather damage and less laborious to maintain.

* Environment and terrain. The prevailing natural environment of the mid-Atlantic region is forested hills. If you live in a housing development, the builder might have bulldozed the land into a flat, featureless plain, or sited each dwelling on a slight turfed rise to "improve" drainage. These artificial landscapes leave buildings exposed to cold or heat and channel precious rainfall into streets, storm sewers or nearby waterways, picking up pollutants as it goes.

The natural terrain consists of high and low places that use water differently and create an environment where a wide variety of plants can thrive. Low areas can be planted with native grasses and perennials because they tend to stay moist longer than higher areas, provided there is no standing surface water. The area must drain. Higher areas enhance privacy and aesthetic interest, and can be planted with native species that manage happily in drier conditions.

It might not be practical to re-bulldoze your land, but adding a berm and a swale along a boundary or at a corner can make a big difference.

If you have the opposite problem, a steep slope, you can use terraces, with or without retaining walls, to slow runoff and erosion. Since it can be inconvenient or even dangerous to mow on a slope, don't use turf; use native grasses and perennials that will adapt to the site.

* Resources and labor. Before you install any feature or plant on your property, stop and ask yourself these couple of questions: Is this going to need constant attention from me? Will this require a lot of water/fertilizer/weedkiller/insect spray? If the answer to either question is yes, you might want to avoid that particular plant. Water shortages, water quality and pollution-bearing runoff from both commercial and residential sources are as crucial a consideration in this area as they are in the rest of the country. Landscaping to make the best use of available water resources saves money and work.

Collect roof-runoff rainwater in barrels, and use it to water plants. You're using rather than wasting an available resource, and avoiding watering with treated water.

Recycling, composting and mulching also conserve resources. Mulching and composting improve soil quality and help make plants more robust.

These steps will help you to sustain your plants for much longer than the conventional maintenance programs that were being practiced 20 to 30 years ago.

* Planting and biodiversity. Choosing the correct plants for a location can minimize the need for water, fertilizer, chemicals and pruning. The best plants are those that mimic the natural landscape. Forest plants have an overstory of taller trees and an understory of smaller trees and shrubs, plus plants that like a lot of water (lower areas) and plants that thrive on less. Occasional clearings make space for more sun-loving and drought-tolerant species.

Having the widest possible array of plants in your landscape will ensure biodiversity in both flora and fauna. Different species of insects, birds and small mammals require different types of habitat and food. Biodiversity is what ensures a landscape's survival. A monoculture, such as a large expanse of the same type of turfgrass, or a foundation planting that consists solely of azaleas, creates a kind of dead space that is not hospitable to a wide variety of creatures. Using native plants is significant because those are the plants that native wildlife depend on.

* Function and aesthetics. There's nothing about sustainable landscaping that is at odds with any aesthetic or functional concern. Your landscape should be both functional and aesthetically pleasing. Walkways, driveways, steps, decks, patios and outbuildings all still have a place and serve very important functions where you need them. Install them so they enhance the property.

Sustainable landscapes are beautiful; practical; and labor-, money- and resource-saving. Creating them may take a little more thought and effort at the beginning, but the results will better sustain all of us.

On Oct. 1 and 2, the 2005 Annual Fall Conference of the Maryland Native Plant Society addresses "Baltimore's Urban and Suburban Forests: People and Plants in Partnership." The topics closely parallel theories written about in this article. Speakers address native plants in the ecosystem; how plants, animals, and soil organisms interact in the environment; how to ensure sustainable forests; and what we can do for stewardship of mixed native plant communities. Conference information is on the Web at www.MDFLora.org/events/fall2005conference.html.

Joel M. Lerner is president of Environmental Design in Capitol View Park, Md. E-mail or contact him through his Web site, www.gardenlerner.com.

A steep slope can be terraced, with or without a retaining wall, to slow runoff and erosion. The key is to take advantage of the area's natural terrain and climate.The best plant arrangements are those that mimic nature as much as possible, thus lowering maintenance and conserving resources.