Happy Spring 2008!
As I contemplated what I was going to write about this year, I recalled hearing one of my favorite speakers, Colston (Cole) Burell, at the Minnesota Green Expo. Cole is a garden designer, photographer, naturalist, and award winning writer. As an avid and lifelong plantsman, Cole is author of several books, including Perennial Combinations and Rodale’s All New Illustrated Encyclopedia of Perennials.
As the featured speaker, Cole talked about his latest guide from the Brooklyn Botanical Garden titled Native Alternatives to Invasive Plants. Listening to his talk was a good refresher for why we do what we do.
First, we need a couple of definitions. Native plants are those plants growing naturally in the area before European settlement. Some call these plants wildflowers, but I find that name too restrictive as it excludes grasses, sedges, shrubs, and trees.
Exotic plants are defined as non-native plants. They have beauty and a purpose, but when they jump the garden fence, THEN I have a problem. Too often we don’t know which exotics will make the leap.
When a plant expands too forcefully, taking light, water and nutrients from less aggressive natives, I don’t plant it in my garden. In addition, if the plant travels farther than what I want, I don’t plant it in my garden. Yet, you still see winged euonymus (burning bush), amur maple, and japanese barberry widely available for sale. As I look out over the meadow of the Kinnickinnic River, I see these exotics.
Why are these plants so popular? They tend to be tough and easy to grow, and they thrive in degraded, compacted soil. Some, like barberry and buckthorn, are full of berries or seeds easily spread by birds and animals.
Some invasive plants have prolific seed production. But so is the ability to grow quickly, to leaf out early or to stay in leaf longer, any of which allows the plant to shade out others and gives it a competitive edge.
Some native plants can be invasive too. But native plants are usually kept in check by other native species (plants or insects or animals), which have been their partners in evolution. Exotics often have no predators or diseases to slow their spread.
People may argue that the area has been urbanized and in agricultural production for so many years, so why not just plant what they want to plant. But Mr. Burrell argues that even places that are not truly wild have a plant history that means something and should be preserved.
Cole remembers the forest before the invasives. He believes that as long as there is a collective memory of what used to be, most people are not willing to watch a flood plain of trilliums and spring beauties turn into a monoculture of buckthorn.
Not only to native plants remind us of what came before us, but benefits they provide for the eco-system. Native plants provide food and shelter to birds, butterflies, bees and insects. They all work in harmony.
At Kinnickinnic Natives, we grow about 95% of our plants from seed collected on our site. Occasionally we propagate from cuttings. We NEVER collect or dig from the wild. Diverse plants are the outcome of our labors.
