The mantra of sustainable horticulture here at URI is “the right plant in the right place”. Then there’s the opposite — “a weed is just a plant in the wrong place”. But more often, a plant in the wrong place is diseased, stunted, wilted,under attack, or just plain dead. Every plant has specific needs or preferences for growing conditions. These include light, moisture, temperature, and soil nutrients. In a site where the conditions don’t match the plant’s requirements, the plant will not thrive, and will be more susceptible to pathogens, insects, and environmental damage. Once this happens, inputs of perhaps pesticides, fungicides, extra water, or fertilizer are needed, which is the UNsustainable part. Or, sometimes the inputs are used as an attempt to prevent the plant’s decline.
The inputs are unsustainable for a wide variety of reasons. They could be made from petroleum, a limited resource. They could irreversibly contaminate the groundwater or kill beneficial insects. When you think about it, even extra watering to prop up a moisture loving plant sited in a hot dry spot is unsustainable. Our clean drinking water is also a limited resource, as we know all too well from the past summer.
Another definition of sustainability within horticulture is:
“…design, construction, operations and maintenance practices that meet the needs of the present without compromising the ability of future generations to meet their own needs” ( American Sustainable Sites Initiative).
So that’s what we try to do. But sometimes it takes a little bit of experimenting to find the right plant/right place. Yesterday as I cut back the peonies around the stage,the Acanthus planted behind them 2 years ago demanded my attention. It’s huge, green, and fresh looking.Very Healthy. The site faces south, in front of a 4-foot stone wall. The Acanthus, a native of the Mediterranean, obviously appreciate the extra warmth that radiates from the stones of the wall and the stage. I went looking for another Acanthus planted the same year. It also faces south, near the rose arbor, but has large rhododendrons behind it instead of stone. This one was puny compared to the one on the stage! A little bit colder, a little more shade, and perhaps a little drier with the huge rhodies behind it taking up moisture. It makes all the difference in the world. I’ll move the small one to a better site.