I recently attended an all-day conference put on by the Chesapeake Conservation Landscaping Council. Over 200 landscape professionals were taught sustainable landscaping practices like organic lawn care and site-specific stormwater management techniques. The organizer who urged me to attend recommended the closing talk by Doug Tallamy above all, so I stayed to hear it and I’m glad I did. I found his talk the most compelling case I’d ever heard or read for the use of native plants, and here’s why:
- Studies have shown that American dogwood (Cornus florida) supports 117 species of moths and butterflies while the Asian C. Kousa only supports one. He cited similar results for other native-nonnative pairs. That got my attention, as it would anyone who loves nature.
- I was open to what he had to say because, as Elizabeth noted, he isn’t preachy, and he acknowledges the difficulties. So I appreciate his bringing a bit of fresh air to what’s become a very contentious argument between nativists and people in the gardening world.
More surprising facts
and woodies are the most important plants for sustaining wildlife because they support the most biodiversity. The surprising part is that in the East, 82 percent of the plants that grew here were oak trees, so it’s no wonder there are comparatively few nonwoody native plants.
He urged landscapers to
- Create corridors connecting natural areas,
- Reduce the total area now used for lawn, and
- Transition to native ornamentals, especially in habitat corridors that run through our backyards and connect them.
Tallamy did a masterful job of making the case that a great number of insects need native plants for their survival. But during the Q&A when he was asked how contractors might convince their clients that they should landscape for insects, he had no answer.
Which brings us back to the question in Elizabeth’s post, whether the "battle for natives has been won." Judging from the reaction of these boots-on-the-ground professional gardeners and designers, not by a long shot and that’s because it’s still homeowners who make these decisions, not entomologists and wildlife ecologists. And because homeowners want plants that look good and are low-maintenance, they’re choosing Cornus Kousa in ever-increasing numbers, especially when advised by professionals in the hort biz, because it’s more drought-tolerant and less vulnerable to disease than our native dogwood. So which plant is more sustainable?
My full report on the conference and the larger questions it raised – especially that unanswered one about how to change clients’ minds – is coming soon.Posted by Susan Harris on December 2, 2007 at 12:02 pm, in the category Ministry of Controversy.