What's Invasive? Telling People What They Can't Plant In Their Yards

My country yard.  So arrest me.

I have very strong ideas about how a civilized society behaves.  A civilized society behaves like Paris, where the mangiest dogs are allowed on the banquettes in finest restaurants on the assumption that everyone, including the pooch, understands how to conduct him- or herself properly.

A civilized society behaves like my urban neighborhood in Saratoga Springs, NY, where the neighbors don't entirely understand why I have hens, but put up with the squawking and even give me a friendly hello in the morning anyway out of a general spirit of tolerance. 

A civilized society makes the fewest rules possible. If it's not hurting you, it's fine for me to do it.  A civilized society is dubious of authority, humorous, and unafraid.

The world of plants is not civilized. I was shocked a few weeks ago, when I wrote about one of the most beautiful moments of my year--the blooming of the flag iris around my pond in the country--only to be called irresponsible for celebrating an invasive plant. Never mind that there is no sign of a problem on my property, though the flag iris have probably been there for 80 years. Never mind that almost all pond plants are potentially invasive, including waterlilies. Is somebody proposing that we do without waterlilies? Because if that is the case, I think I resign.

The Center for Invasive Species and Ecosystem Health at the University of Georgia even includes hemerocallis fulva, the orange roadside daylily, on its list of problems. Hemerocallis fulva is just so graceful, with its long stems and small, cheerful upfacing trumpets, that it makes driving around my part of the world in July a total joy, and I hate driving. 

One of the great delights of a country landscape is the naturalized plants like these that thrive by themselves and form a piquant bridge between the wild and the cultivated. But nothing that is not at least a little thuggish naturalizes.  Should our world therefore be nothing but weeds and overbred, super-fussy garden plants?

Naturalized daylilies are easily controlled by mowing if they get out of bounds. I've got them everywhere in my yard, and have noticed no spreading whatsoever. This is not purple loosestrife, which when established, simply cannot be pried out of the ground--not in my part of the world, at least. 

Take a look at this list of herbaceous plants reported to be invasive. It includes all kinds of old-fashioned garden plants like hollyhocks, geraniums, several veronicas, lilies of the valley, even several clovers. I don't know how aruncus dioicus escaped censure, since it's seeding itself everywhere in my yard. Isn't every plant that grows easily from seed potentially invasive? 

Maybe you consider this list informative.  To me, it suggests a profound paranoia and lack of trust. It is the product of a culture I don't want to join.

My feeling is, if it's invasive in your yard, get rid of it. If it's not invasive in mine, be quiet.

Here is how the Center for Invasive Species And Ecosystem Health defines the problem: "Invasive species, if left uncontrolled, can and will limit land use now and into the future."

Exactly right. That control is called gardening. So the problem is not the plants, it's people who neglect their land. But nobody who is reading this site is neglecting his or her piece of property.

So can't we just be adult and admit that, as Michael Pollan pointed out in his brilliant first book Second Nature, the battle for an ungardened landscape has already been lost?

We're not going to restore our pre-Columbian ecosystems, no matter what, for myriad reasons, including the size of our population and all that carbon we've been spewing into the air since the Industrial Revolution. The plants that are native to your area may well be struggling because of all the things we've already done to our environment, so planting "natives" may well mean planting something native to another ecosystem anyway.

Can't we instead be as civilized as your average Parisian mutt and stop barking at each other?  Let's face it, unless you have a staff of half a dozen taking care of your yard, every garden needs at least a few thugs just to take up room and do what they do best, which is add a brutal vitality to the scene.

Comments

[JW]

A-men. Having bought a 150-year-old house in Syracuse about year ago, we are still discovering what comes up here as we try to organize organic beds the groundhogs won't eat and fight some ground away from the Japanese knotweed. There are lovely sweet-smelling yellow lilies and pretty purple spiky things whose names I don't know, being from another part of the country. I want them teased out from the weeds so I can see what they'll look like given a chance to thrive, not killed off, regardless of whether someone else thinks they should live or not. Is suspect the purple spiky thing might be one of the "invasives" you refer to. Don't care. It's pretty, and it grows here, not were I come from.
Jane

[Holly]

Uggg. I hate it when there is too much interest in how I do my stuff.

I have the yellow flag iris and I love it! It does beautifully in my sometimes-under-water-backyard. I also have white loose strife that I keep under control by ripping out what I don't want.

and then there is the snow-on-a-mountain. Most people hate it, I have the variegated flavor and although I rip it out freely, I don't do that everywhere as it makes a pretty border that can be mowed over and comes back.

I like to grow things that *grow*. I want flowers but I have a wicked bad combination of swamp-behind-my-house and clay soil that discourages some of the less hardy plants. My ground is often soggy and I never ever ever have to water back there. So things like roses that are not considered to be invasive simply rot and look awful.

I'm with you....leave me alone, I'm not hurting anyone with my choices and who made them the Garden Police anyway?

[naomi]

Whereas for you yellow flag is not a problem, here in NOLA it took me several months to eradicate (it was pushing out the native irises). And, I'm sure bananas and elephant ears can safely be grown in your yard, while here it took almost almost a year to dig up all those bananas, which weren't even tasty. The elephant ears, well, I do what I can. Pentas have taken over my lilies but perhaps this year a freeze may come and push them back so the lilies can thrive for a bit. But I'll never plant Queen Anne's Lace, nor a few others which I can't keep to my yard - if a gardener can't restrict it, don't grow it.

['nora]

Preach on, sister.

[Julia]

I've found that pretty much everything I grow in my British garden is considered highly invasive and a noxious weed in the USA. Some of my most recent acquisitions include Lygodium japonicum, the climbing fern, Salvinia auriculata, a floating fern, and Saururus cernuus, the lizard's tail.

The UK has a very small list of invasive plants that we are not allowed to plant - giant hogweed, giant kelp, Japanese knotweed and Japanese seaweed. Everything else is fair game!

[rainymountain]

What is invasive in one part of the continent is well-behaved even hard to grow in another. I am in agreement with you about civilised societies, Michele, and about our inability to go back to a pre-columbian landscape. Wherever humans have gone, the most invasive species ever, they have taken plants and seeds with them either by intent or inadvertance.

[invisiblebees]

It's interesting to me that so many plants are forbidden, but so many chemicals and chemical combinations are not.

[El]

Frankly, I like all the "invasives" that have escaped as the Ghost of Gardens Past out here in my country plot. Mostly seen in early spring, they're creeping phlox, blue hyacinth, snowdrops, Dutch iris, bearded iris, some odd tulips...and then ajuga has naturalized in all lawn areas. Considering it's been 30-odd years since a flower gardener lived here, these things do herald a bit of joy for me, even if they show up in the most un-garden of areas. What's the alternative? Well, native poison ivy, native creeping charlie, couch grass...

[Tatiana]

This sounds like an excellent gardening Libertarian manifesto. I only wish more people understood that their boredom and 'friendly concern' infringes on their neighbors right to choose. Luckily we're not overly restricted here, but still - no chickens for us. Not for any valid reason, just an old rule enforced by people who assume the worst.

[Anne (in Reno)]

Eh, invasives out here are apparently more noxious and less pretty. I'd rather try and keep stuff alive that I like than fight through knotweed, cheatgrass and variations on the theme of thistle. But this is the desert, so maybe I shouldn't be gardening here in the first place.

Just don't come crying to me when somebody gives you some beautiful water hyacinth. Pretty and sturdy isn't always enough in my book. But I'm not talking about irises and daylilies. Very few people are as responsible and sensible as you folks are about this stuff. We're not living with Parisians, at least not out in my neck of the woods. These are people who think tamarisk is pretty so they'll plant it in riparian areas to make them look nice. And we will never be able to get rid of it. But it's so PRETTY. There comes a point, we have to assume some level of responsibility as gardeners and know that not everyone is as sensible as we are. Just go to Oregon and ask about the beautiful English ivy.

[Teresa O]

I would rather see tiger lilies and chickory coloring the roadside. Instead, the county and residents mow the ditches leaving behind a yellow/brown strip that runs along side roads. I've been known to put up signs that say, "DO NOT MOW," because I find joy in Queen Anne's lace growing with wild abandon.

[trey]

I agree with the tone of you article except for one small part.
"...as civilized as your average Parisian mutt"? I don't know if things have changed in the 25 years since I was in Paris, but it was quite common to find the "dog ends" of these "civilized" mutt's all over the streets. People would allow them to do their business, and then just walk away, leaving it for someone else to step on.

I found it quite shocking, but I suppose it's not the fault of the dog, but rather the "uncivilized" owner. Maybe things have changed.

[Judy Lowe/Diggin'It]

A double hurrah for this post! I've often had similar thoughts. Poor butterfly bush is now drawing howls that "it's invasive!" whenever I write about it. For some people, Buddleia davidii may be invasive if it escapes, but should everyone have to dig up all their buddelia bushes for that reason?

I want to be responsible, but I'm not convinced that orange ditch lilies are a threat to the environment.

[David]

This was a really unfortunate post; and does a disservice to your readers. Supporting planting invasive plants seems like foolish attempt at justifying your plant selection and naiveté of the effects a gardener can have. Gardeners are responsible for the introduction of many invasive plants in this country that have caused significant ecological damage. In addition, the amount of resources and money for their control is astounding. Instead of trying to convince you, I encourage your readers to look at the many examples of invasive species and their impacts, there are plenty of resource available, from popular books (including two of my favorites, Gardening with a Wild Heart, Bringing Nature Home), to peer reviewed publications, or any number of websites pertaining to invasive plants, and plant and wildlife conservation.

[Katie]

I think a key to what you were saying might be found in the phrase: "on the assumption that everyone, including the pooch, understands how to conduct him- or herself properly."
Sadly, not everyone knows what they are doing. Oriental bittersweet may look lovely but I've spent days pulling it out of my dogwoods and shrubs. Why? It's a tree killer.
I suggest that folks who want to know more about the hoo-haw on native versus non-native plants read Bringing Nature Home - it's an eye opener. Unless you think you'd enjoy a butterfly and bird-free world, practice intelligent, thoughtful, considerate gardening. No, there is no gardening police, but you (and we all) will reap what we sow... There, now I'm done ranting....

[arythrina]

I think you've hit on an important subtlety that often gets overlooked: "invasive" is not a categorical distinction: on or off, yes or no. There are degrees of invasiveness, depending on the cultivar, the climate, the gardening methods employed.

I am, however, happy to see massive lists like the one you label as paranoid. More information is better: I'd rather be too conservative to start and loosen up later than allow a total thug to romp all over my yard without realizing it. Good gardeners should be consulting multiple sources. A truly free society encourages the spread of information - it's in the diversity of opinions that we slowly hone in on truth.

[Susie]

I agree with you David. Some of us live in areas where invasive plants can easily go rampant & destroy native ecosystems.....amazing the nurseries still sell them.

[mr_subjunctive]

Wow. I'm genuinely shocked and appalled by this post, and I don't think that's happened to me at Garden Rant in, like, forever. Well, maybe that time Amy dissed houseplants.

We're not going to restore our pre-Columbian ecosystems, no matter what, for myriad reasons, including the size of our population and all that carbon we've been spewing into the air since the Industrial Revolution.

Otherwise known as "as long as the noose is around my neck, I may as well jump off the horse" logic.

Just because you and your readers believe themselves to be responsible gardeners who would not release an invasive into the wild doesn't mean everybody could be trusted to do so. Also, tastes vary. I happen to think creeping Charlie is pretty, especially when it's in flower. Can I move in next door and plant my yard full of it? You can trust me. I have a blog! So I am a responsible gardener!

Perhaps if you were willing to put your money where your mouth is, and agree to pay some percentage of eradication costs for any plant designated invasive that escapes cultivation in your area. Maybe then. But "trust me, I'm a good steward of the environment" isn't quite enough for me, I think.

Also, El, FYI, two of your three "native" plants are actually introduced invasives:

Couch grass (Elytrigia repens) is an invasive species native to most of Europe, Asia and NW Africa.

Creeping charlie (Glechoma hederacea) is an invasive species native to Europe and SW Asia. If memory serves, it was even deliberately introduced as an ornamental. (You still see it in the houseplant / container gardening books occasionally.)

But I'm sure the people who brought it here really meant to keep it in check. (They just got really busy, and then one of the kids got really sick, and then there was the fire, and before you know it, whoops, it was everywhere. So, y'know, sorry, but hey: it wasn't a pristine landscape to begin with, so no real damage done, right?)

[Squirrelgardens]

WOW...if it isn't the turf police then its garden police.

Love the post about chemicals in yards are fine...but watch out for the snow on the mountain.

I live in the meatball shrub and white rock capital of the world....so no matter the neighbors will complain. Would miss the whining.....NOT.

[frank@nycgarden]

This is a difficult topic. No, not one of us can save the forest from garlic mustard (remember that post??) or eliminate the beautiful purple loosestrife from the wetland. When I choose to do without a beautiful, but invasive plant, I am sacrificing something for the sake of something larger. I will be perturbed by my neighbor's refusal to do so.

Ecology and gardening are not the same, rather obviously I suppose. Ecology regards larger systems and study of plant, mineral, and animal life far greater than what an individual who gardens is typically capable of seeing in their yard.

Aesthetics are rarely a good reason to dismiss ecological concerns. I like yellow over blue is really not good reasoning when it comes to Flag. Form follows function, but as gardeners we're often seeking the reverse.

We can dismiss the state of affairs, look the other way, and get all Individualist on Earth's ass if we want. Or we can make compromises, ask ourselves what we can live without.

The vast majority of plants we grow in our gardens are not a threat to healthy plant communities the world over. However, some are, maybe not in our neck of the woods, but as the bird flies and craps.

Nature doesn't seem to care much for native or not. The strong will go on, spread. Strength speaks for itself. But one thing we humans should have learned about strength is that it often comes with a price.

Our self-awareness drives us to deeply consider the changes we have wrought over a short period of time in the Americas.

I grow weeds from Europe and Asia (dayflower, smartweed). I grow dames rocket, an invasive mustard from Europe/Asia because my wife is emotionally attached to it (although she recently found a suitable alternative), I grow native goldenrods, asters, eupatorium, ferns. I grow roses and lilies, sages and sedum.
On Weeds:
http://nycgarden.blogspot.com/2007/10/our-weeds-part-1.html
On Ranting about Invasives:
http://nycgarden.blogspot.com/2009/06/my-brain-has-turned-to-kudzu.html
On Finding Native:
http://nycgarden.blogspot.com/2008/02/brooklyn-native.html

No answers.

[Michelle]

There seems to be an underlying assumption among gardeners that a plant has to be from some far-away land in order to be pretty. And there is another assumption among gardeners that gardening should be free from research and ethical decisions. I am sad - this is the first time a post at garden rant has made me sad.

Please come learn more about the issues surrounding non-natives and invasive species over at the Wildlife Gardeners forums: http://www.wildlifegardeners.org/forum/index.php?referrerid=139

[Joseph Tychonievich]

The whole issue of invasive plants has been hyped to a huge degree in a way not supported by science. A few invasive species are demonstrably incredibly destructive, such as kudzu in the southern US, but even the infamous purple loose strife has little evidence to back up its bad image. Hager and McCoy (1998) published a review in the journal Biodiversity and Conservation that concluded: "We traced the history of purple loosestrife and its control in North America and found little scientific evidence consistent with the hypothesis that purple loosestrife has deleterious effects."
It is time to be more reasonable and enjoy lovely flowers without guilt.

[Deb]

Do no harm. Its a doctor's motto and should be a gardener's motto also.

[Michelle]

Also, for those of you who believe you can perpetually contain colonies of invasive plants in your yard: when you lose your job and forclose on your house, will you diligently kill all of the offending plant? And then revisit each year for however long it takes to kill every seedling left behind from those plants?

[Deb]

There is a great book, "Native Alternatives to Invasive Plants" published by the Brooklyn Botanic Garden that is available for those who would like to replace their invasive plants with something better.