Sweetgum (Liquidambar styraciflua) is native to my neighborhood... |
You may recall that, a few posts ago (“Wind and Weather,” August 17th), I vented my annoyance with the NWS and NOAA for using the word “normal” for their computed 30-year averages. (Check out my new gadget at right, Acronyms Explained.) When I read an exchange in American Nurseryman about regulating “invasive” species—those quotation marks again!—I had a similar reaction. “Native” is as nebulous a concept as “normal.”
...while Rhododendron catawbiense, native to western North Carolina, does poorly on the coast; and... |
...and crape myrtles (Lagerstroemia indica x fauriei) came from the Orient. |
People who really, really want a native garden should buy a large parcel of land and just encourage (and perhaps impose a little structure on) what’s already there. Indeed, I would argue that all “gardens” are by definition artificial, the result of human will worked on the land.
Philosophy aside, the flip-side of what makes a species native is what makes one non-native. Except for recent introductions whose provenance is (somewhat) known, it can be really hard to tell who’s whose horticultural daddy. Sylvan and Wallace Kaufman point out in the first three chapters of their excellent book, Invasive Plants (see Good Reads at right), that all “natives” were once successful invaders.
Trans-Atlantic transport circa 1670 |
To illustrate the difficulty inherent in defining “native,” I present a Homo sapiens example. Both Tim and I were born in United States to parents who were also born in the United States. No one from either family (the documented ones, anyway) is indigenous to the eastern U.S. My ancestors hailed from all over Western Europe, and it’s anybody’s guess how they ended up there. Two or three lines of my family had established themselves in North America by the latter half of the 17th century. Yep, I’m certified DAR and UDC (check out that acronym gadget mentioned above). But am I more native than Tim? Both sets of his grandparents sailed from Ireland in the 1890s, some 220 years after my folks got here. Besides, with all due respect, even the “Native Americans” came from somewhere else—can you spell “land bridge”?
Welcome to the New World, circa 1900 |
Invasives poster child, kudzu (Pueraria lobata) |
The best definition of an invasive is “a plant that is too successful.” Its trademark trait is the speed with which it takes over an area. Examples of When Plants Go Bad in the South include kudzu, Asian wisterias, Japanese honeysuckle and Chinese ligustrum (a.k.a. privet). New York battles purple loosestrife and milfoil. In the Middle Atlantic states and the Northeast, burning bush, barberries, and Miscanthus cause problems. South Florida fears nandina, melaleuca, and many, many others. The Irish suffer from troublesome volunteer butterfly bushes growing in their gutters and chimney pots. And so on.
The Invasives Alert page from June 2011's Fine Gardening |
There’s also the local character of invasiveness to factor in: for example, kudzu’s not a problem in Minnesota.
Anyway, the challenge facing both the horticulture industry and gardeners boils down to avoiding being part of the problem. Most states’ Cooperative Extensions post lists of local potential invasives on the internet, as do watchdogs like the Nature Conservancy, the Invasive Plant Atlas, the USDA Plants Database, the National Invasive Species Information Center, and Invasive Alert. Connecticut leads the way in outlawing flora non grata, legislating against anything that’s invasive anywhere. (In fact, I’m considering relocating there, as they must have already handled the important stuff like universal health care, unemployment, education, immigration problems, and the shrinking of the middle class. You think?) If you suffer from technophobia, as I do, call your Extension or State Department of Agriculture: they will sigh heavily and eventually mail you something. The Kaufmans’ book has a long list of sources of information as well.
Looking for alter-"natives"? |
Check out these books by Allan Armitage or C. Colston Burrell |
So get informed before you plant. And whatever else happens, don’t you be slipping in a cutting of kudzu to cover your new pergola. Unless you live in North Dakota.
Kathy
P.S.—You may want to invade Plant Delights Nursery’s Fall Open House. It's being held the weekends of September 9-11 and 16-18. Weather’s nicer now, if you weren’t up to facing the summer do.
No comments:
Post a Comment