Ok, this is going to take some time, patience, and more than one post. This is a controversy in the gardening community on the scale of Global Warming/Climate Change in the environmental community. What IS a native plant anyway? Minnesota was covered in ice about 10-12 millenia ago (except for you characters in the "Driftless Area" of Southeastern MN). Which means the slate was fairly well wiped clean. Plants gone. So we could reasonably look at a time frame of between then and now for "What's a native plant?" But about 350 or a few more years ago those amazing French fur traders started paddling west in their oversized canoes with mud on their boots from not only the East Coast, but some of them didn't scrape before they started paddling up the St. Lawrence Seaway, or wherever they first touched "America". Thus started the invasion of plant species from other continents, and from the East to the West.
Fur traders were followed by Pioneers, not just human, but also the plants they brought with them from their home environments. People like to bring pieces of their former environment to their new one to avoid feeling strange in a strange land. And they unwittingly brought the mud on their boots and the feed for their animals and the resultant dung from their animals.
So, most descriptions of native Minnesota plants use a time frame between the glaciers melting and the Europeans arriving. It's a start. Not conclusive in some peoples minds, but a start.
I want to insert here, for the sake of building the controversy, another blog, much more established, and probably also more credentialed than I. Though I will not defer to credentials alone, rebel that I apire to be. Here's Doug Green's Blog, which I just found using Google, and which from my other searching appears to be somewhat representative of typical gardeners' opinions about native plants. This blog appears to have an abundance of interesting gardening ideas and info which I hope to explore further. I will note that he does seem to belittle native plant proponents as having a "politicized charge", whereas he and his kind, being artists, are after simply an esthetic production, an appeal to the senses, a sense of respite. Sounds good, we all are looking to connect with beauty, a sense of peace, ourselves, or maybe "Nature", whatever we might describe that as.
I agree with him that a garden is an artificial construct, no matter how well constucted. Even an arduously researched and planned prairie restoration is a "garden", a construct of human choice. But it is far different from simply an ephemeral work of art designed just to please the senses and to fit the artists mood and space. It has certainly taken into consideration plants that evolved together with each other and also with a multitude of other critters in a certain proximity to the soils and climate of the geographical area. It thus has a more true ring of genuineness to an area historically than an assemblage of plants however lovingly placed in the ground simply by the whim of the artist's esthetic choice.
To be continued...
and I leave you with the above, Polemonium reptans or Jacobs Ladder, blooming last year about May 18th.