The problems with "invasive"

Researching vines, I happened upon the WORST real-gardener reviews I've ever seen for a plant - for the trumpet vine, aka Campis radicans.  Read all about it on its Daves Garden plant profile.

Or I'll summarize for you:  33 positive reviews, 24 neutral and 47 negatives!  The negative reviewers used LOTS OF CAPITAL LETTERS and verbiage like:

• "Horrible!"
• "Beware!!"
• "Kill the Beast!"
• "Killed some of my trees."
• "It can penetrate asphalt driveway."
• "I hate this vine with a passion."
• "I will celebrate the day that it becomes illegal to sell or plant this vine."
• And almost everyone used the term "Invasive."

The only problem with calling this plant "invasive" is that it's an American native, and the feds have defined "invasive" as a nonnative plant that behaves badly (to summarize).  So for purposes of getting funding to remove bad plants, only the bad nonnative plants qualify - a battle that invasive/native plant expert John Peter Thompson fought, lost, and still gripes about, citing deer as the most obvious native species that's grossly out of control.

Indeed some readers of Daves know the legal definition and object to its use for this native vine, one suggesting the term "rambunctious" be used, as it was on a "pro-trumpet vine website" she'd found.

MORE HELPFUL TERMS, PLEASE
It seems to me the legal definition of "invasive" may work for purposes of invasive species removal in natural areas or to warn people whose gardens are adjacent to natural areas.  But when it comes to the typical urban or suburban landscape, the term is virtually useless. 

Gardeners need to know how plants behave IN GARDENS.  If they seed, are the seedlings easy to remove or not?  After all, spreading aggressively is an asset for plants being tasked with lawn replacement, unless the gardener's budget allows for spacing plants cheek by jowl.

My local hort club faced this problem not long ago when members were describing the plants they were giving away at the club's plant swaps as "invasive" and confusing the hell out of everyone.  The word got out and people asked, "Why's the local hort club distributing invasives?"  (And no, nobody was giving away Japanese honeysuckle, an actual invasive in this area - the term was being misused to describe plants that spread, period.) But aside from the bad press, potential recipients of "invasive" plants wanted to know more, and always shot back with "In what way?" and "Is it hard to get rid of?"

But it might help if we used "invasive" in the context of natural areas and gardens that abut them, and something else to label plants as potential thugs in the garden, and I have a few I'd like to nominate for that second category, starting with bishop's weed and houttuynia.  It would also help if we identified where bad plant X is invasive, or in what types of conditions, since plants can behave very differently in different places.

Oh, and good native alternatives to trumpet vine are:

• Crossvine, aka Bignonia, about which there are no negative reviews on Daves Garden.
• Honeysuckle, about which Dave's readers rave.

Trumpet vine photo source:  Wikipedia.

Comments

[Bob Vaiden]

I use the term "aggressive" for native plants that take over easily. There are many native plants that are great for a "civilized garden"... and some that are not!

I always warn folks about cupplant... don't plant it near the zinnias:) And even I am removing common goldenrod... it already covers the countryside, and there are many other beautiful species of goldenrod to have in the garden.

[John]

I was caught off guard at one of the first plant swaps I hosted when someone had offered nice rooted cuttings of Eleagnus - Russian Olive, generally a weed shrub in this area and what I consider invasive. When I got through explaining its faults the very hurt gardener that had brought it explained that deer don't eat it. More than half the swappers wanted some upon that simple attribute.

Now I try to explain aggressive spreaders with terms like "might be a problem" and "in some gardens" rather than the blanket - do not plant this.

One person or one group of people will never be able to define the complexities of nature in a way that satisfies everyone.

[Claire Splan]

Just as important as making a plant's invasive habits known is making its means of invasion known. Is it an aggressive reseeder or does it send out runners? If the problem is runners, it can be planted in containers with no problem. If it's a reseeder, that's a lot harder to control.

I think terms like "invasive" and "native" make sense only in a militant plant nazi sort of way. Even to call trumpet vine an American native--I mean, what does that really mean? A plant that originated in the northeastern or southeastern U.S., for example, is probably less suited for my garden in California than plants that originated in Mexico. After all, nature didn't draw the borders, people did.

[Reading Dirt]

"Invasive" means non-native to that area, and with a thuggish tendency to spread and crowd out natives. A well-behaved non-native isn't usually considered "invasive."

If you've got a thug in the garden, the proper term is "aggressive." Or to borrow from the nursery catalogs, "This lovely ground cover will spread enthusiastically!"

[Pam J.]

Today's NYT has a good article on this very subject.
http://www.nytimes.com/2008/09/09/science/09inva.html?_r=1&scp=1&sq=invasive%20plants&st=cse&oref=slogin Personally, I like the word "invasive" because it's succinct and precise, and I have long since given up even thinking about what's native and what's nonnative. It just has no meaning to me on my little 1/3 of an acre. If something grows on the planet Earth I consider it native.

[tai haku]

As has been noted the problem with defining invasive by reference to nativeness is how does one properly define nativeness - nationality? ny state? by county? Quite the predicament.

For "natives" I woud use "aggressive".

[Rosella]

Houtynia! I don't know nor do I care if it is native here or in Outer Mongolia, because it is (in my garden) the single worst garden thug I have ever encountered. I have had to resort to brush killer to keep it from invading my perennial and vegetable beds, because I tried pulling it out when I saw it put its nasty little head up, only to find that it will regrow from any teensy root node left in the ground.

Honestly, I have 1/3rd of an acre and I try to not plant things that cause real problems, but the list of problem plants seems to grow faster than I can keep up with it. In this area ampelopsis has become a major problem -- it is almost as bad as kudzu, but it is still being sold by the local nurseries with the enticement of "pretty blue porcelain berries". I have never planted it, but it is Everywhere in my garden now, and I spend a lot of time pulling it up.

[Andrew Semprebon]

One of the main benefits of planting "Native" plants is that they are more likely to fit ecologically and do well on your site - but that means you have to be pretty specific about what is considered native. Unfortunately, most sources only identify "US Native', which is next to useless for this purpose.

[karen]

This was a fun article. Thank you! I've been offered trumpet vine many times and I always say "No thanks!"

FWIW I think aggressive and invasive doesn't say much especially since we live in different climates.

This is more helpful-
Does not play nicely with other plants.
Self sows to a fault!
Spreads via underground rhizomes!
Covered 10 ft of garden in 3 yrs!
Triples in size every year!
Plant with other thugs or mow around it..

This info is much more helpful don't cha think?
Karen

[Samme]

The house I live in has a lovely huge trumpet vine growing up one side of the house. It is in full gorgeous bloom right now. I had no idea it was considered to be a 'bad' plant. I have lived here 3 years and it has not spread much, it dies back a little in the winter, then returns the next year. The hummingbirds love it and so do I.

[Barbara]

Love the trumpet vine!

HATE Japanese stilt grass which is taking over, smothering wildflowers along the roadside, and clogging seasonal stream bed!

[Michele Owens]

There are really beautiful old trumpet vines in my part of the world. I read all those cautions on Dave's Garden before planting the pair that are now climbing my garden shed--and decided that what's true in Florida, is not necessarily true in Zone 4. We'll see.

American Bittersweet is a complete pest in my Saratoga Springs garden, Zone 5. I constantly have to hack the neighbors' vines back, and I'm forever cutting seedlings out of my flower beds. It's a strong plant, so the seedlings won't pull out of the ground.

[Annie in Austin]

Susan, I think there's an inherent problem in trying to use one word to describe a plant's behavior. Focusing on the perfect 3 syllables is great for haiku but aren't phrases and sentences more useful for telling another gardener what to expect?

Deer are not my favorite animals, but they helped to keep a gnarled old trumpet vine from engulfing our previous Austin yard, browsing all new growth below the 6-foot line while the hummingbirds buzzed around the flowers at the top. I wasn't too sad to leave it behind, and planted the coral honeysuckle instead.

Michele, I'm not sure about zone 4, but when I lived in Zone5/IL, shoots from a neighbor's trumpet vine traveled 70-feet to pop up in my borders. So good luck!

Annie at the Transplantable Rose