The question of whether something is native or not comes up a lot. Leave aside the question of how do you know what a given plant is, how do you decide if it grew here before European intervention. Often the label will say "Native" somewhere, but native to where. if a given species is native to North America, does that make it native to Minnesota? I will use a few examples to illustrate the confusion.
I will be using a set of maps aquired from the Biota of North America program. For more information on these maps and how to interperate them you can see my prior post here.
There is obvious confusion with this plant with it's numerous hybrids and cultivars. Two species are important in horticuluture. Monarda didyma and Monarda fistulosa. Monarda didyma is a tall plant with bright red flowers and it grows well in shade and rapidly spreads to fill an area. It is promoted as a native and is very attractive to pollinators. What's more, it is easy to grow here. The question is, is it native to Minnesota? Not really.
From this map Monarda fistulosa is widespread in most of the state of Minnesota.
What about a more suprising group of plants that the purist in me did not expect.
Coneflowers
E. angustifolia is native to Minnesota, but it doesn't extend to the eastern two thirds of the state. It is a true Great Plains species and doesn't grow in our oak savannas or tall grass prairies.
Obviously, there is nothing wrong with growing a plant even if it is not historically native to your area. Many insects still visit the flowers and birds will happily eat their seeds. But if you are a native plant purist seeking a representation of what your landscape would have looked like before the native plants were extripated, it is important to realize where those plants actually grew and more carefully select the plants you choose to grow in your garden or yard.
That is so especially true here on the western side of the Rockies, in the PNW. Many of the online nurseries that specialize in natives grow none of our natives, they are all from the eastern side of the country.
ReplyDeleteI love BONAP and use it often, but it should be noted that it is not 100% accurate. Even their website says "relatively complete" "BONAP plans to provide updates of these maps at regular intervals". For example the Illinois map of Monarda fistulosa shows that it is native to all but about 5 or 6 counties. It would be a good bet that M. fistulosa is native to those counties also. That said, BONAP is still the best source on the web for distribution info.
ReplyDeleteNice post. I'm certainly a purist when it comes to native plantings, especially in restorations. However, as Jay says, you have to be aware of the limitations of maps showing native ranges. Another thing to consider is that as the climate changes and humans continue to impact the landscape, restoration targets may need to change as well to fit today's (and future) environmental conditions. If we aim to restore a landscape that was present in the 1700s-1800s, yet we have a different climate today and may have a very different climate in 50-100 years, we may be setting retoration projects up to fail in the long-term.
ReplyDeleteBefore I had much experience with restoration, like you I assumed that Echinacea purpurea must be native (to Indiana) because it was in every prairie seed mix I'd ever seen. I later learned that it was likely not in the Indiana counties of the Chicago Region (and in most of Indiana for that matter) prior to settlement, and that it prefers a bit of shade (not full sun). Try as I might, I could not get it removed from "native" restoration seed mixes where it did not belong. It isn't invasive, so it probably doesn't cause much harm being included, but as a purist I don't like it.
Doug Tallamy had an interesting take on native range of plants... he said something to the effect of if the plant's insect hosts are present (and native), then he considers the plant native to that area. Hopefully I'm not misinterpreting his statement too badly.
As Doug Tallamy was saying, the important thing to me is that local insects can utilize the plant because they share an evolutionary pathway with it. Secondarily, I want the plant to do well. For example, heucheras hybridized using a large proportion of PNW native heuchera genetic material do not do well here in Pennsylvania, and I don't consider them native. On my blog and at my nursery, I try to say what part of North America the plant is native to and specifically if it is native to PA. I use the USDA maps.
ReplyDeleteAlison,
ReplyDeleteI promise it gets better. Nurseries will follow consumer demand, I've seen it. Before long, there will be nurseries springing up to supply native plants for most of the niches of the pacific northwest.
Jay,
I was probably overly enthusiastic to imply that BONAP is 100% accurate. It is the best I've seen yet that covers whole ranges of species, but it has a lot of limitations. The herbarium data they use is not complete and it is impossible to show the nuances of where something grows in a national map. They also suffer from a lack of data from the state of Georgia.
Scott,
It's hard being a purist. There is so much we don't know and can't account for. Accuracy is a moving target and every year we learn a little more. We can only guess what the landscape actually looked like in previous centuries and we can only guess what it will look like in the future. But we can also predict that it will change. Climate change will have a definite effect on our ecosystems. Native ranges changed in the past and they will continue changing into the future in response to changes (Human and otherwise). I think it is important to help fill in the spaces between native habitats as best we can to allow our native species to move from one island of remnant habitat to the next. It's a shame that we have broken up our quilt of habitat and it's our responsibility to stitch it back together again.
Doug Tallamy is right. Many insects and other creatures can follow the plants if we let them. There are many species that we don't understand and don't move to what seems like good habitat (Karner Blue butterflies). But that depends on your restoration goals. Our coneflowers have plenty of insects and I'm sure it helps native bees and honeybees alike even if it didn't grow here without our help.
Carolynsshadegardens.com,
I certainly agree that native plants behave differently when outside their original habitats and range. I've seen sunflowers blooming way off schedule because they were the wrong ecotype. That is why I get the most local variety of species that I can. I'm sick of asters blooming after the first killing frost. Thank you for making an effort to communicate where your plants come from at your nursery. I appreciate it.
I enjoyed this post. My gardening is quite hodge podge, and the plants that are native grow along side some that aren't. I am trying to focus on getting more native plants, though. In doing my reading on the subject, I have found that some people consider a plant native only if it is from the same stock that is already growing very close by. I am not organized enough to attempt that, though. Maybe you've already blogged about that. I don't keep up with blogs very well.
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