I was asked a question last week about ‘sustainability’ and planting only ‘native plants’ in the landscape. At the time I gave an off the cuff answer that didn’t really answer the question but simply confused the questioner (and myself) enough to allow us to talk about something else. (Perhaps I should go into politics?) But the question did not go away; something about it bothered me so I decided to give it some serious thought. So here are my serious thoughts about sustainability and planting native plants in regards to the landscaping at Rose Villa.
First some definitions of sustainability;
Merriam Webster dictionary says; “using a resource so that the resource is not depleted or permanently damaged.”
Wikipedia; “In ecology the word describes how biological systems remain diverse and productive over time.”
A United Nations conference in 1987; “meet present needs without compromising the ability of future generations to meet their needs”
My own thoughts are that sustainable systems should be flexible, adaptable, and able to change to accommodate the pressures put upon them. The sustainable landscape, be it the parking lot of a supermarket, the back yard of a home containing 3 children, 2 dogs and a barbequing husband, or a retirement complex, all have different needs, resources, and expected productivity.
In regards to the landscaping here at Rose Villa; the green foliage of the various shrubs, trees and lawns creates a peaceful cooling atmosphere, the bright warm colors of seasonal flowers, blossoms and again, foliage creates interest and an atmosphere of friendliness. The resources of Rose Villa include the natural fertility of the Northwest soil, the abundant rainfall 9 months of the year, the relatively mild weather year round and the human resources of both the grounds crew and the people living here.
Is the landscape here at Rose Villa planted with native plants? Before I answer that I have to ask; “What is a native plant?” Is it a plant that grows in the wild meadows, forests and wetlands today? Or is it one that grew in the northwest 200 years ago when Lewis and Clark first traveled here from the east? Or is it a plant that was growing here 2,000 years or 2million years ago?
People are not the only way plants travel, they move around on their own as well. Ancient roses have been discovered to be in every part of the Northern Hemisphere long before people started moving roses around. Rhododendrons were here in the Northwest long before Europeans settled on the east coast. Is it just the wild Rhododendrons that are native or could the hybridized rhododendrons of the last 100 years also be called native? They fit in here and live here just as well as the wild rhododendron.
An argument can be made that some of the grasses that were here when the pioneers first came into the Willamette valley had migrated from the east coast after the pilgrims brought them over from Europe to feed their cows. So are these native grasses or are they invasive species?
And finally; the environment throughout the Northwest is not the same as it was even as short a time ago as when Lewis and Clark came over the mountains. And in and around the major urban areas the environment is even more radically different. Will plants that are labeled as ‘natives’ be as sustainable in an urban environment as they are in the wild? I think not. I think that there are many plants that are not labeled “native” that are more sustainable in the urban environment then the ‘natives’. And I think we as landscape maintenance professionals have a responsibility to acknowledge this and plant accordingly, sustainably.