Green Landscaping

Content provided by Donald De Fever, CLP, LEED GA,
President, Jensen Landscape Services

Landscaping is an area where building owners and managers have the opportunity to both conserve water and prevent pollution by ensuring Best Management Practices (BMP’s) are used at their properties.  In addition, resource and water conservation measures will attract new, environmentally-cost conscious prospects to your properties. 

Water costs are on the rise.  Current indications suggest that water costs are expected to increase well over 10 percent during the next 3 years.  Reducing costs sometimes requires an initial investment to achieve the ultimate goal of mitigating recurring expenses.  Landscape water use conservation methods can pay-off within 18 months, a reasonable rate of return in any economic market.   Irrigation experts have identified that as much as 15 - 35 percent of water cost savings can be realized by implementing disciplined management practices as a part of your water conservation initiatives.  By creating a practical, yet disciplined conservation plan and on-going implementation processes, your water savings may yield far more than short term gains – you will have the opportunity to defer recurring costs within the foreseeable future.  Up front investments will compound savings going forward and tenants, stockholders and future investors will recognize your prudence and responsible decisions.

In LEED® and USGBC language, there is a triple bottom line for benefits.   People.  Planet.  Profit.  Those are the three “P’s” of being environmentally responsible.  Below, please find a list of Best Management Practices (BMP’s) to achieve Landscape water use reduction:

  • Identify and repair broken irrigation system components with thorough irrigation diagnostic surveys delineating the problems.
  • Improved efficiencies in existing irrigation components.  Consider alternative methods to improve water distribution and infiltration without run-off or other water waste contributors.
  • Program water scheduling with soil, plant type, time of year, irrigation component, slope factors, hydro-zone and water budget parameters. 
  • Consider landscape assets and their utilization.  Do you need three acres of turf for sports fields or reconstruct into strolling and specialty gardens?
  • Mulching bare soil will control weeds, retain soil moisture, reduce soil temperature, and decompose into valuable nutrients.
  • A pragmatic water budget can be developed and managed, just like your operating fiscal budgets; report actual costs verses projected costs and therefore manage wisely.
  • Deep root irrigation for specimen trees, shrubs, groundcovers, and even turf (aeration) will provide water availability and better plant health with above BMP’s.

Recycled water use considerations:

  • Determine through local city or county if recycled water is available.  Local water wholesalers such as the Santa Clara Valley Water District can help research reclaimed water use sources.  Their link is  http://www.valleywater.org
  • Determine if water source connections are feasible for your property, then evaluate and understand the available water quality of that source.
  • A landscape horticulturist professional can help you determine if the available water quality is acceptable for your plant types and agronomics as well.
  • The water quality and sediments analysis will also be of interest to determine if irrigation systems will endure the new source of water.
  • Recycled water is typically 40-55 percent less than the cost of potable water.

Green waste diversion from landfill:

  • “Point source” reduction of waste is a key to LEED® performance, no matter if it is recycling bottles and cans or green waste.
  • In certain conditions such as Redwood Tree group plantings, let the natural “duff” or leaf drop accumulate into natural mulch.
  • Use mulching mowers whenever possible.  Valuable nutrients are returned to turf and no additional thatch build-up is proven.
  • Whenever possible, use natural mulch such as tree chips from arborist companies in certain parts of your landscape.

”Green” products and materials versus pesticides:

  • Integrated Pest Management:  A pest management strategy that focuses on methods that are least injurious to the environment. Pesticides are applied in such a way that they pose the least possible hazard, and are used as a 'last resort' when other controls are inadequate.
  • Any word with an “icide” is a pesticide.  Fungicides, pesticides, herbicides, etc…reduce the use on properties and implement a more “biotic” practice.
  • Understand existing economic and aesthetic thresholds of pest control in the landscape.  An insect free landscape is not necessarily a healthy one.
  • Certain biological organisms such as nematodes, parasitic and pathological organisms can be used in place of insecticides.
  • Mulching mineral soil can mitigate the need for weed control herbicides.

Green Roof, Green Screen, Tree Canopy attributes

Green Roof:  A “green roof” is a partially or completely covered roof-top with vegetation and a growing medium planted over a waterproof membrane.  It may also include additional layers such as a root barrier, drainage, and irrigation systems.  The term of “green” roof refers to the growing trend of environmentalism.  Jensen Landscape has built and maintained many green roofs.  Our most well-known project is installed at the California Academy of Sciences (CAS) located in San Francisco, CA.   CAS has a 125,000-square-foot rooftop to accommodate a living tapestry of native plant species.  The more typical black tar-and-asphalt building rooftop leads to a phenomenon called the “Urban Heat Island” effect. The endless swath of black rooftops and pavements trap heat, causing cities to be 6 to 10 degrees warmer than outlying greenbelt areas. One-sixth of all electricity consumed in the U.S. goes to cool buildings. The Academy of Science’s green roof keeps the building's interior an average of 10 degrees cooler than a standard roof would. The plants also transform carbon dioxide into oxygen, capture rainwater, reduce storm water run-off, and reduce energy needs for heating and cooling.

Green Screen & Green Wall:  From trellis systems to crawling plants on a building surface and free standing landscaped amenities, green screens-walls provide cooling and privacy factors to buildings.  More often, green screens are being used in architectural aesthetics, as well as reducing air conditioning costs.

Tree Canopy:  In LEED® language, trees mitigate “heat island effects” with cooling hardscapes such as parking lots and sides of buildings.  Deciduous trees can shade in the summer time and sun can penetrate the leafless trees to warm the building in the winter time.

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