I agree that there is a place for exotics, but are there natives in our gardens too? “Right plant right location” should mean more though than planting a rose bush in a sunny spot. Many of our natives are being improved right now, baptisia and echinacea being prominent stand-outs, and that is a very encouraging step in the right direction. As gardeners we need to look to the plants in our region. As much as I love lavenders, I try to use agastaches and penstemons because when I hike into the mountains, that’s what I will find, not to mention that the native penstemons of the West are incredible.

We need to not just consider plants because they will do well in our environment–that’s the English approach–but choose plants from our environment. The English neglected their own native plants at the expense of foreign introductions to such a degree that their native plant heritage is virtually lost. Twenty years ago the idea of this happening in North America seemed unfathomable, but the rate at which we are losing our open spaces to climate change and encroaching populations, as gardeners we need to preserve our native plant species. As Al says, it’s a moral issue.

As for soil ecology, really we’re only beginning to understand how it works. The organic movement has made us more aware of this, and it is doing wonders to revolutionize the way we think about agriculture but it has had the downside of introducing several questionable practices like promoting vermiculture. The practice is commendable, but it poses the risk of introducing a foreign worm–the red worm into an non-native environment. Is this any different than what the Jamestown settlers did when they unloaded their worm-laden ballast? Worms aren’t the only source of controversy–the popular addition of commercial mycorrhize could potentially have problems. Like the yeast bacteria that makes sourdough, every region has its native mycorrhize in the soils already. By adding commercial mycorrhize to the soil, you are introduce yet another non-native species. What kind of effect it will have on native populations isn’t certain, as it’s a newer practice.

Personally, rather than second guessing ourselves in the garden, I think the best solution for any kind of conservation is to use what you’ve got and plant native/indigenous plants, a philosophy I’ve had to embrace even more now that I’ve moved into the western U.S.

Wow, this is long and rant-ish. Sorry!