Energy Efficient and Environmentally Responsible Landscaping – An Introduction

1. Energy Efficient and Environmentally Responsible Landscaping – An Introduction Prepared by Debra Rowe, Ph.D. dgrowe@oaklandcc.edu Prepared for CERET under a grant from the National Science Foundation

2. Why should we care about energy supplies? It is a national security issue causing the following threats to our well being: • Political Instability • Economic Instability • Environmental Instability

3. Political Instability = Dependency on foreign oil • The U.S. imports 54% of its oil consumption. • U.S. oil production has declined continuously since 1974. Thanks to John Richter for this slide Source: University of Minnesota

4. Political Instability = Dependency on foreign oil Much of our oil comes from Middle Eastern countries whose policies we don’t like

5. Economic Impacts "Paid predominantly by the US, the costs of protecting our Middle East oil supplies are as high as $15-25 a barrel - that is about a dollar a gallon.” Peter Hain, UK Europe Minister USS Stark, 1987

6. Economic Instability • Globally, the largest item in the U.S. trade deficit is our importing of foreign oil • Nationally, our economy is hampered by energy costs which decrease the bottom line of profits and economic health • Locally, people on stressed budgets - many have to choose between heating and eating

7. Environmental Impacts - Disease “… power plant particle pollution causes more than 603,000 asthma attacks per year..” Source: Abt Associates: Death, Disease, and Dirty Power Plants Thanks to John Richter for some of these slides.

8. Environmental Impacts - Death “Abt Associates finds over 30,000 deaths each year are attributable to fine particle pollution from U.S. power plants.” Source: The Clean the Air Task Force

9. Burning Fossil Fuels Produces the Greenhouse Effect and Climate Change 4

10. Disruptions of food production More extreme weather events Unknown disruptive effects on cosystems Spread of disease to temperate climates Submersion of land masses – up to 45 feet of sea level rise 140,000 deaths per year attributed to climate change Sources: Intergovernmental Panel on Climate Change (2000 scientists from around the world; EPA of the U.S. ) Environmental Effects -Climate Change

11. Terrorist threats Centralized power plants are much more vulnerable to terrorist attacks than distributed generation via wind, solar and other renewable energies

12. Why should we care about energy supplies? It is a national security issue causing the following threats to our well being: • Political Instability • Economic Instability • Environmental Instability

13. What can we do about it? • Learn energy/environmental literacy as it relates to landscaping • Become environmentally responsible landscape designers, technicians, marketers, etc. • Provide upgrade training to existing professionals in architecture, construction, landscaping, HVAC, building inspectors, community planners and more • Make better choices as consumers/investors

14. Energy Efficient Landscaping Landscaping is a natural and beautiful way to keep your home cool in summer and reduce your energy bills. In addition to adding aesthetic value and environmental quality to your home, a well-placed tree, shrub, or vine can deliver effective shade, act as a windbreak, and reduce overall energy bills.

15. Energy Efficient Landscaping Reduces Our Dependence on Fossil Fuels and Saves Energy And Money! Carefully positioned trees can save up to 25% of a typical household's energy used for heating and cooling. Computer models from the U.S. Department of Energy predict that just three trees, properly placed around the house, can save an average household between $100 and $250 in heating and cooling energy costs annually.

16. Energy Efficient Landscaping Reduces Pollution Too! Studies conducted by Lawrence Berkeley National Laboratory found summer daytime air temperatures to be 3° to 6°F cooler in tree-shaded neighborhoods than in treeless areas. That could be a 9 to 20 % savings in cooling costs. The energy-conserving landscape strategies you should use for your home depend on the type of climate in which you live.

17. Landscaping and Your Regional ClimateThe energy-conserving landscape strategies you use should depend on which region you live in. The United States can be divided into four approximate climatic regions: temperate, hot-arid, hot-humid, and cool. See the map to find your climatic region.

19. Temperate Region – This includes Michigan • Maximize warming effects of the sun in the winter. • Maximize shade during the summer. • Deflect winter winds away from buildings. • Funnel summer breezes toward the home.

20. Hot-Arid Region • Provide shade to cool roofs, walls, and windows. • Allow summer winds to access naturally cooled homes. • Block or deflect winds away from air-conditioned homes.

21. Hot-Humid Region • Channel summer breezes toward the home. • Maximize summer shade with trees that still allow penetration of low-angle winter sun. • Avoid locating planting beds close to the home if they require frequent watering.

22. Cool Region • Use dense windbreaks to protect the home from cold winter winds. • Allow the winter sun to reach south-facing windows. • Shade south and west windows and walls from the direct summer sun, if summer overheating is a problem.

23. It's also important to consider your home's microclimate in your landscaping strategy. Your home's microclimate may receive more sun, shade, wind, rain, snow, moisture, and/or dryness than average local conditions.

24. Microclimate (continued) • If on a sunny southern slope, you may have a warm microclimate, even if you live in a cool region. • Even though you live in a hot-humid region, your home may be situated in a comfortable microclimate because of abundant shade and dry breezes.

25. Microclimate (continued) • Nearby bodies of water may increase your site's humidity or decrease its air temperature. • Microclimatic factors also help determine what plants may or may not grow in your landscape. .

26. Shading • Deciduous trees with high, spreading crowns (i.e., leaves and branches) can be planted to the south of your home to provide maximum summertime roof shading. Trees with crowns lower to the ground are more appropriate to the west, where shade is needed from lower afternoon sun angles. Trees should not be planted on the southern sides of solar-heated homes in cold climates because the branches of these deciduous trees will block some winter sun. • Although a slow-growing tree may require many years of growth before it shades your roof, it will generally live longer than a fast-growing tree. Also, because slow-growing trees often have deeper roots and stronger branches, they are less prone to breakage by windstorms or heavy snow loads. Slow-growing trees can also be more drought resistant than fast-growing trees.

27. Shading (continued) 3. A 6-foot to 8-foot (1.8-meter to 2.4-meter) deciduous tree planted near your home will begin shading windows the first year. Depending on the species and the home, the tree will shade the roof in 5–10 years. If you have an air conditioner, shading the unit can increase its efficiency by as much as 10%. 4. Trees, shrubs, and groundcover plants can also shade the ground and pavement around the home. This reduces heat radiation and cools the air before it reaches your home's walls and windows. Use a large bush or row of shrubs to shade a patio or driveway. Plant a hedge to shade a sidewalk. Build a trellis for climbing vines to shade a patio area.

28. Shading (continued) 5. Vines can also shade walls during their first growing season. A lattice or trellis with climbing vines, or a planter box with trailing vines, shades the home's perimeter while admitting cooling breezes to the shaded area. 6. Shrubs planted close to the house will fill in rapidly and begin shading walls and windows within a few years. However, avoid allowing dense foliage to grow immediately next to a home where wetness or continual humidity are problems. Well-landscaped homes in wet areas allow winds to flow around the home, keeping the home and its surrounding soil reasonably dry.

29. Landscape windbreaks • Basically, a windbreak can lower the wind chill near your home. Wind chill occurs when wind speed lowers the outside temperature. For example, if the outside temperature is 10°F (-12°C) and the wind speed is 20 miles per hour (32 kilometers per hour), the wind chill is -24°F (-31°C). A windbreak will reduce wind speed for a distance of as much as 30 times the windbreak's height. But for maximum protection, plant your windbreak at a distance from your home of two to five times the mature height of the trees. • The best windbreaks block wind close to the ground by using trees and shrubs that have low crowns. Dense evergreen trees and shrubs planted to the north and northwest of the home are the most common type of windbreak. Trees, bushes, and shrubs are often planted together to block or impede wind from ground level to the treetops. Evergreen trees combined with a wall, fence, or earth berm (natural or man-made walls or raised areas of soil) can deflect or lift the wind over the home. Be careful not to plant evergreens too close to your home's south side if you are counting on warmth from the winter sun.

30. Landscape windbreaks (cont.) 3. If snow tends to drift in your area, plant low shrubs on the windward side of your windbreak. The shrubs will trap snow before it blows next to your home. 4. In addition to more distant windbreaks, planting shrubs, bushes, and vines next to your house creates dead air spaces that insulate your home in both winter and summer. Plant so there will be at least 1 foot (30 centimeters) of space between full-grown plants and your home's wall. 5. Summer winds, especially at night, can have a cooling effect if used for home ventilation. However, if winds are hot and your home is air conditioned all summer, you may want to keep summer winds from circulating near your home.

31. Landscaping Water ConservationYou can design a landscape that not only conserves energy but also water. Here is a brief overview of some water-conserving landscaping strategies.XeriscapingXeriscaping is a systematic method of promoting water conservation in landscaped areas. It's based on seven principles:

32. 1. Planning and design Provides direction and guidance, mapping your water and energy conservation strategies, both of which will be dependent upon your regional climate and microclimate. 2. Selecting and zoning plants appropriately Bases your plant selections and locations on those that will flourish in your regional climate and microclimate. 3. Limiting turf areas Reduces the use of bluegrass turf, which usually requires a lot of supplemental watering. 4. Improving the soil Enables soil to better absorb water and to encourage deeper roots. 5. Irrigating efficiently Encourages using the irrigation method that waters plants in each area most efficiently. 6. Using mulches Keeps plant roots cool, minimizes evaporation, prevents soil from crusting, and reduces weed growth. 7. Maintaining the landscape Keeps plants healthy through weeding, pruning, fertilizing, and controlling pests. Xeriscaping is mostly used in arid regions, but its principles can be used in any region to help conserve water.

33. WateringIf you can determine how much water your plants actually need, then you won't overwater them and waste water. It is important to not only understand a plant's particular watering requirements, but also evapotranspiration.Evapotranspiration is the amount of water that is evaporated from the soil and transpired through the plant's leaves. This amount of water needs to be replaced through watering. If you know your area's Et rate, you can plan the amount of water to be replaced through irrigation. Call your local water district or cooperative extension service and ask about your Et rate. However, your particular microclimate will also affect evapotranspiration in different areas of your yard. Also, it's best to water or irrigate your plants in the early morning when evaporation rates are low. This also provides plants with water before mid-day when the evaporation rate is the highest.

34. Additional Resources on Water Conservation Evaluation Tools 1. WaterAideDOE Building Energy Software Tools Directory 2. Xeriscaping: Creative Landscaping - http://www.ext.colostate.edu/pubs/garden/07228.htmlColorado State University Cooperative Extension 3. XeriscapingToolbase Services 4. LandscapingH2ouse.org - California Urban Water Conservation Council

35. A note about solar energy. If designing a building to use solar: Unobstructed access to the sun is necessary for the optimum performance of active and passive solar energy systems. There is generally no guarantee a solar system will always have unobstructed access to the sun. Every day, decisions about the built environment and landscape effect the future shading of existing or potential sites. Solar access protection is clearly advantageous for the following systems in the associated locations: Rooftop- solar water heater and space heating collectors and photovoltaic arrays South facing walls- passive solar systems such as Trombe walls, attached solar greenhouses, and direct gain systems such as windows and glass Lot (south-facing)- ground-mounted or detached active collector systems.

36. Permaculture Permaculture philosophy is landscaping and agriculture that works with, rather than against nature to create sustainable human environments. It is sometimes described as low maintenance, low energy and oftentimes edible landscaping. For more information, go to ATTRA - National Sustainable Agriculture Information Service at http://www.attra.org/attra-pub/perma.html

37. In conclusion: • Landscape practices can help or hurt ecosystem and human health • There are principles of environmentally responsible landscape design that should be incorporated into all landscaping projects • There are precedents and resources to assist you • What you do makes a difference