I went to a spectacular lecture today at the U. S. Arboretum. I found out about it because I recently joined the Arboretum as a Friend for the mere pittance of a $35 contribution. I encourage all my buddies out there to join and attend some programs with me. This was the program I saw. Below the announcement, I have written up some notes to share about some pretty exciting advancements in
Measuring Sustainability in the Garden
Dr. Steven Windhager
There is a great deal of talk about creating sustainable gardens, but how do we assess the level of sustainability in a garden? The SSI (Sustainable Sites Initiative) has been formed to provide guidelines and performance benchmarks for those who want to create and measure sustainable landscapes. The goal is to quantitatively asses the attributes of all types of sites in order to measure success in maintaining or improving the health of an ecosystem. Learn about the SSI, including what it is, why it is needed and how it affects public gardens and other landscapes.
Dr. Windhager is the director of the Landscape Restoration Program at the Lady Bird Johnson Wildflower Center and serves on the Steering Committee and as Technical Advisor for the SSI. His expertise includes Sustainable Site Design, Ecological Restoration, and Urban Ecology.
Lecture Notes |
On average, 30 to 65% of a family’s daily potable water is used in landscaping (what a bummer to learn this!). Strategic planting of 1 canopy tree can eventually conserve 25% of a home’s energy use. We all need to think macro in order to make actual gains in living greenly. Conservation is all well and good, but, we have the opportunity to reverse some of the detrimental impact we’ve had on our own environment in terms of climate change by designing “sustainable” landscapes, big and little.
To achieve true sustainability, we must satisfy 3 intersecting criteria: economic vitality, social acceptability, environmentally sound science. In other words a yard needs to be affordable, look great and add up to a sum gain in energy use when you consider ALL factors in it’s creation and care. He gave the example of a commercial property where a pond for storm water abatement is put behind a building and fenced off with ugly chain link. While this pond may, at first, do it’s job, it’s been shown that it is soon ignored and then not maintained properly, falls into dis-repair and soon enough is no longer effective.
So it’s important to measure carefully and precisely. That’s where the Lady Bird Johnson Wildflower Center came in. Maybe a decade ago, they wanted to become LEED certified (Leadership in Energy and Environmental Design), but there they found there were no benchmarks for landscape design similar to those developed for architecture and building. So they began working on guidelines for sustainable methods and benchmarks for performance in landscape design. The Sustainable Sites Initiative, a system where “credits” are appointed for design that meets particular criteria (available at www.sustainablesites.org/.) They encourage design that for example, uses very little or no potable water for irrigation (only gray water like captured A/C condensation) and keeps storm water from ever running off a site and much, much more. They even give credit for plastic pot recycling programs. This initiative also shows how to measure sum gains realistically. Dr. Windhager spoke a lot about assessing the starting point of any site. Is it a ‘Green”, “Grey” or “Brown Field”? A Green Field describes a site that has no previous building on it. A Grey Field is a site that has had building but is not contaminated with any toxic chemicals, and you can guess what a Brown Field is.
He also said that the costs of sustainable design are front loaded in the design phase, but can often be built for less. He recommends that every project include a Soil Plan that addresses potential compaction, how it may be mitigated or how bulk density may be restored and to bring organic matter to acceptable or improved levels.
The guy was a wealth of knowledge in this realm and explained everything clearly. If you ever get a chance to hear him speak, please do. One of his most potent pieces of advice: Never Ever Use PEET. It traps too much carbon in the soil. Enjoy.