A green roof in Austin, Texas, designed by the Lady
Bird Johnson Wildflower center. Green, sustainable and eco-friendly are buzzwords on the collective consciousness. Consumers can make greener choices when they buy groceries, build and furnish their homes—and even tend their gardens. Over the last few years, the American Society of Landscape Architects (ASLA), the United States Botanic Garden and the Lady Bird Johnson Wildflower Center have banded together with other national organizations to launch the Sustainable Sites Initiative.Steve Windhager, director of the Landscape Restoration Program at the Lady Bird Johnson Wildflower Center in Texas, was among representatives from various landscaping organizations who gathered at Brookside Gardens in Wheaton, Maryland, in February to speak at the “Green Matters: Sustainable Landscape” symposium. He outlined the initiative and shared some the most important facets of environmentally conscious landscaping.
Landscape professionals emphasize the importance of native plantings, which play a crucial role in water conservation and quality. While this may seem like common sense, in our modern age of global exchange today’s homeowners have a wide array of exotic and specialized plants imported from all over the world at their disposal. Windhager warns that the use of imported plants overlooks the necessity of native plants in the local ecology, as well as the adverse effects that invasive plants can have in an area. Native plants are already adapted to a region’s climate, “which means that within a similar habitat zone, they are ready to survive on just the rainfall that would naturally fall, and will be able to handle both the extremes of temperatures in the summer and winter,” he says. Plants not adapted to our area can require excessive amounts of watering to survive. In addition, non-native plants chosen for their quick growth often require greater maintenance and are shipped long distances—two factors that contribute to wasted energy in the landscape.
Water waste and contamination are also concerns. Half of the water used in landscaping—which can account for up to half of the treated water a city produces—is used inefficiently. Proper irrigation, plant selection and runoff management help to limit water waste. Consider where the rain runoff on your property goes, and look into how it can be utilized. A green roof can provide an additional source of water filtration and flood mitigation. Rain barrels, water gardens and other forms of water collection can distribute runoff throughout the garden, reusing it to irrigate plant life.
The quality of the water that leaves your property is another factor to consider. “Plants naturally remove many nutrients from our waters that would otherwise cause problems in our creeks, rivers and lakes,” says Windhager. “We can use them as a natural sponge and filter to improve water quality on our property.” This goes hand in hand with the importance of soil health. Soil health can be affected by contaminants used in home construction, or simply through the use of pesticides and other chemicals in landscaping. Reducing soil health will adversely affect the health of your plants by reducing water infiltration and nutrient availability, making your garden more difficult and more expensive to maintain. This is another area in which native plantings can be more durable than imported ones since native species are usually more resistant to pests.
Many botanical experts recommend Integrated Pest Management (IPM), which outlines a common-sense approach to dealing with garden pests. It starts with understanding and accepting a tolerable level of safe pests and, when necessary, controlling pests using the safest and most natural methods first, avoiding harmful chemicals that can cause toxic run-off.
Another important role that vegetation plays is its part in the natural cycle of capturing and storing carbon dioxide. “There is no way to go carbon neutral without utilizing the landscape,” says Windhager. Different types of plantings filter varying amounts of carbon. Building calculators allow you to estimate the amount of carbon emitted by your home construction, and a landscape expert can help you translate this number into how much green space and what types of plants you should use in whatever size space you have.
Aside from safeguarding the quality of air, water and soil on your property, properly located trees and plantings can provide natural heating and cooling, which in the long run will reduce your energy consumption.
Native plantings thrive in this garden.