In 1987 a United Nations Commission, eponomously named the Brundtland Commission after its chair Gro Harlem Brundtland, argued that sustainable development is “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” In addition, as Dr. Brundtland put it, “the environment is where we all live and development is what we all do in attempting to improve our lot within that abode. The two are inseparable.”
As people interested in horticulture, whether we are “developing” our own small plot of land at our home or a larger commercial property, we must begin, or further in some cases, to take into consideration the inseparableness of our development actions and the environment. Many of you have most likely heard of LEED certification, which is a third-party green building certification administered by the U.S. Green Building Council. It focuses primarily on the building envelope and the building systems and technologies. Fewer of you may have heard of the Sustainable Sites Initiative. This is a similar third-party certification program but it is still in the development stages and is not planned to officially roll out until 2012. The guiding principle of this initiative is to “preserve or restore a site’s sustainability within the context of ecosystem services-the idea that healthy ecosystems provide goods and services of benefit to humans and other organisms.”
Clearly there are tangible and real benefits to healthy soils, healthy plants and good water management. As horticulturalists and plant people these are some of the areas that we touch in our work. Healthy soils is really where it all begins. I am a landscape contractor and I believe strongly that our industry does not do nearly enough soil testing. As observant professionals we can generally know an area’s soil type but a lab test can provide valuable information about the idiosyncratic needs of a particular soil. Our goal is to provide nutrients and activate microbial life in the soil to feed the plant life. To this end my company has had good success with compost tea and a balanced fertilization program. We brew and apply our own tea and have the ability to customize the brew according to the needs of a particular site. The photos on this page show a property that we have applied tea for the past four years along with natural, slow release fertilizers. There have been virtually no pesticides used here during that time. Soil tests confirm a much healthier and biologically active soil than when we started the transition from a conventional fertilization program. We spray the tea directly onto the turf and planting beds as well as a foliar spray on the plants. Three to four applications per year has proven to be effective. Where chemical-based pesticides and some synthetic fertilizers can kill a range of beneficial organisms that improve plant life, compost tea adds to and promotes what some soil folks call the “micro-herd” of beneficial organisms. If you’re like me though and not a soil scientist I have found the website for Soil Food Web www.soilfoodweb.com to be helpful and educational on all matters around compost tea. The Tea adds the biology and our fertilizers add the nutrition to feed not only the plants but the biological microherd. We’ve found that one without the other is not nearly as effective.
In the landscape world here on the West Coast it is common to use a fir or hemlock bark mulch to topdress planting beds. While bark mulch serves to retain moisture and shade soil reducing weed seed germination it adds nothing to the soil biology, in fact natural toxins in the bark can actually create a net loss from a biology standpoint. Good gardeners have long understood the benefits of using garden compost as a topdressing. Good compost not only has the beneficial organisms that help with moisture retention and weed control but also gives us added nutrient value. Think of it as feeding the soil microherd that in turn sustains your plants. In my recent experience finding quality compost in bulk though can be a challenge. Compost facilities rely on contractors and others to supply them with yard waste that they process into a usable product. Controlling what comes into their facilities is difficult though and as a result in my business we are seeing a lot of plastic, think yard waste bagged in black plastic. Vigilance and feedback to our suppliers will hopefully ensure a consistently quality compost.
Water supply and water quality are two other areas that deserve our focus and innovation if we are to meet the needs of future generations while currently meeting our own. By many estimates up to 50% of summer water use is for landscapes and 50% of landscape irrigation is either wasted or unnecessary due to overwatering, overspray, poorly adjusted heads or leaks in the system. Needless to say, there is huge potential for improvement and water savings. The advances over the past decade or so in irrigation technology have really given us the opportunity to realize these improvements and efficiency gains. There are rain sensors, wireless remotes, central controllers, flow controls, two wire technology, weather stations, and the list goes on. Just like with plant material though, you can have the most incredible availability of plants but if you don’t have the design or installation skills to properly place and install those fantastic plants the advantages are lost. The greatest technologies in the world are rendered moot without a skilled operator. Either get educated or get help.
Another opportunity that I see relating to water is around stormwater management. Look along any waterway during a storm event and you can find any number of pipes coming in to dump the stormwater coming off of our streets, our parking lots and our homes. We’ve all probably heard of planning for the 100 year flood event. Well, planners and developers using this cyclical historical data are finding that water levels associated with the “100 year event” are being reached more and more frequently. As development goes so goes piping into our waterways. Smart developers though are finding alternatives. Through the use of rain gardens, bioswales and phytotechnology we have the ability to handle the large majority of any storm event right on site, to cleanse the pollutants from the storm runoff and to slow the flow into our waterways to minimize the sharp spike in water levels. Phytotechnology is the science of putting plants to work to provide ecosystem services. Absorbing stormwater and cleansing pollutants is an ecosystem service. The City of Portland has a downspout disconnect program that pays homeowners to disconnect their downspouts from the city sewer system. Directing the flow then into a rain garden where plants and soil can absorb the stormwater is a practical and attractive solution that avoids simply running the downspout into a lawn or other area to create a messy bog. We’ll need more of this type of incentive program to encourage and educate homeowners and developers to protect our waterways from the negative impacts of “conventional” development.
I have twins that will be nine by the time you are reading this and while they are just starting to be conscious of the larger planet and world outside our family, their school and our town I have real concern for them of what our planet will be like when they’re my age. I want to do what I can do to ensure that we are meeting the needs of the current without compromising the ability of my kids’ generation, and their kids’ generation to meet their own. As horticulturalists, landscapers, gardeners and plant lovers there are many opportunities for us to take the lead in creating a sustainable future. Pick one and do it.
This article first appeared in the Sep 2009 edition of Pacific Horticulture magazine.