gg, i was so impressed with your very articulate exposition on this topic- that I read it slowly and out loud to My Love.
Occasionally visitors to the 'retum will notice our many Berberis- and comment on the Invasives list. The response that I give is usually rather harrumpphy . I talk about how parts(just parts) of the official 'Invasives' list in Ma.were written for Reader's Digest level education, whereby the intricasies of this barberry or that barberry are believed to be too complex for the average buyer/gardener, so the whole barberry genus is lumped into the Invasives category. Berberis, the 'wild' one that grew here on our property when we moved here 23 yrs ago- THAT i have seen bird-seeded around. But all my berberis cultivars- aurea, helmond's pillar, rosy glow, etc etc etc- in my 23 years here- i have never seen them pop up here or on abutting properties.
And berberis is not on the Invasives list in abutting states.I buy mine in Ct. I woud imagine that other 'Invasives' lists from other states- must also share these problems.?
end of rant. I can't help myself; it just makes me sooo mad!! Other thoughts on this?
best,
mindy

Posted by duluthinbloomz4 (My Page) on Sat, Jul 24, 10 at 18:29

Nothing I'd appreciate more than a "harrumpphy" response - like the capacity to make certain distinctions without having them dumbed down for me just isn't there. Harrumpph, indeed!

Posted by gardengal48 PNW zone 8 (My Page) on Sat, Jul 24, 10 at 21:45

While I certainly do not want to inflame or prolong any personal disagreements various posters may have, I'd just like to say that I have NO issues with Mindy's capture of my comments and her reapplication of them to another thread. As long as attribution is given to anyone's words, I don't see why they cannot be used and reused as the user deems appropriate :-)
In fact, I'd like to thank Mindy for moving this topic to its own thread. It is one that I feel rather strongly about and one that I think is often confused by many hobby gardeners. I'd just like to encourage anyone who makes any comments - and ALL opinions are welcome - to do so with a degree of tact and politeness. This topic can create firestorms on other forums that have extended to dozens of responses and some that tend to take on very confrontational, even rude tones. Let's not have that happen here.

Enuf said. Now please play nice ladies !!

Unfortunately I am in the process of removing my japanese barberry and replacing it with New Jersey tea shrubs because of my concerns about the invasiveness of the barberry. I wish it wasn't the case because I do like the little things (and digging out a thorny shrub isn't easy) but I feel it is the right thing to do when there is a chance that letting the barberry stay is harming the environment.

Just because you don't see the plant spreading in the nearby landscape doesn't mean that birds aren't possibly eating the seeds and spreading it to nearby forests or other natural areas. There are a lot of very pretty plants that are at least not potentially invasive, if not native, that could replace it.

The article I am linking to this post has this comment on the issue:
>>
Mark Brand, professor of ornamental horticulture, Plant Science and Landscape Architecture Department, University of Connecticut, does genetic studies on feral barberry plants to determine their source. He especially looks for purple parentage. DNA fingerprinting of old, invasive populations of barberry originally showed meager evidence of purple barberry contributing genes to wild plants. "We did find a little bit but it didnÂt seem as though these populations were largely produced by the purple leaf types," he says. In another sample, however, parentage analysis of the genetics showed that plants had indeed spread from an old purple plant in an old landscape. "That study did show that a large, old, established, standard-sized purple plant could contribute seedlings to surrounding unmanaged areas."

Ehrenfeld likens low levels of long-distance seed dispersal to a still-humongous 1% microbial resistance to anti-biotics. "In Highland Park, every third house has a barberry hedge. If we were adjacent to a natural area and even if only one percent of those seeds were moving into a natural area and only one percent of that had managed to germinate, thatÂs still substantial, especially because there is so much effective dispersal thatÂs local with bushes spreading out vegetatively and seed dispersal thatÂs local.

Here is a link that might be useful: Article about barberry's invasiveness

thanks summer, for all that info and the link. Right now, it seems to just be referring to one person's research so I will be very interested when the sampling gets bigger.

as to subs for berb. aurea and helmond's pillar,rosy glow, etc.,i do so wish that there were eqivalents in color, shape, size. but there are not.i think we grow all the z. 5 shrubs that are deep purple and bright yellow, and i certainly wouldn't choose to work with those nasty berberis thorns if there were other choice equivalents!!
best,
mindy
www.cottonarboretum.com/

p.s. the mark brand referred to in your post is the brother of Andy Brand, the talented head at Broken Arrow Nursery!!(cool, huh, 2 talented hort. guys in one family?!)
best,
mindy

From my understanding of the scientific definition of invasive, any exotic plant that naturalizes in the wild IS invasive, in that it has displayed the ability to spread to natural areas on its own and thus displace native flora. Perhaps the plant is only a little bit invasive, or perhaps a lot invasive. One thing that worries me, is that it could be possible for an invasive plant species to evolve or hybridize and become more aggressive or invasive over time. That it could also become invasive in new regions of the country.

Something else that bothers me - the horticulture industry has for decades introduced a barrage of exotic species and cultivars, and a few have become invasive and had a distastrous effect on the natural environment. How do we know that one of this year's new plants won't become the next Oriental bittersweet in 50 years?

I disagree that the Massachusetts Prohibited plant list is Reader's digest level - it's a list to regulate the horticulture industry (since it hasn't done a very good job of regulating itself) and even prohibits gardeners from propagating or transporting these plants. Any gardener who is aware of this list and truly educates themselves about invasive plants, is not your average gardener IMO.

For the record, I grow mostly native plants and don't have the interest in exotic plants from faraway places that many gardeners seem to have. I am not a purist and have many ornamental non-natives like Lilacs, Peonies, etc. but those have been growing in the northeast US for centuries now and are clearly not going to take over the countryside. And I almost didn't respond to this thread - finding tone somewhat argumentative and condescending ("play nice"?).

i was just thinking about this issue more and one of the things i realized is this:
Each state has its own "Invasives" list ( for correct nomenclature,see terrene's post above). So I can't buy barberry here in Ma. but I can buy it and sell it in abutting Ct.

What I realized is that this 'point of contention' is the same as it is for many laws in our country.So while the inconsistency of the lists , or the laws, can be maddening, that very same inconsistency is what makes our country great- for allowing diversity on some issues,from state to state.

Aside from the constitutional law aspect, states differ in their invasives lists for many reasons. One reason that I think is CRITICAL to remember- is that , while an albizia tree may be invasive in georgia , it is not invasive in the north because the prolific seeds can't survive the colder climes. Same can be true for reasons of soil conditions, pests, etc.

terrene, i hear your concern about "might today's new plants be tomorrow's invasives?" but i think only a botanist/horticulturalist/plant breeder, who deals with all the federal regulations in their field- could address that question with accuracy. You mention bittersweet; I think of gypsy moth/silk worms and ailanthus/trees of heaven; and there are thousands more..... My guess is that, with all the recent horticultural industry restrictions on invasives- that guidelines/restrictions for plant breeders- pay alot of attention to this issue(or will soon) but my guess is certainly NOT an informed one.

any plant breeders out there?
best,
mindy

I used to have a mature NATIVE box elder tree in my yard. Four years ago I had it cut down because it was too close to the house and the box elder bugs were driving me nuts. The stump was ground out a foot or so below the soil by a certified professional tree guy. Every summer, I get tons of suckers popping up from the surrounding roots. The certified tree guy has been out two years in a row with his grinder to ground out more roots that surround where the original tree was. He said he's never seen anything like it, and he's been doing this for years.

I've poured brush killer on the suckers and the roots, but more suckers just pop up elsewhere. I've dug down to the roots that the suckers are growing from and chainsawed the roots and removed parts of them that I can get out. But more suckers are popping up at this moment. I want to plant a garden in this area, but am afraid to because of this issue with the tree. This is the tree from hell. I'm about to lose my mind! I'm starting to think the only thing that's going to get rid of this tree is Armagedden.

Moral of the story (two of them actually):
1. Native isn't automatically synonymous with good or even desirable
2. Never plant a box elder tree

Deanna

This is an interesting debate But I believe the more important issue that is not being discussed is should we hold arboretums and the information they disperse to a higher standard? Mindy could you share with us where other Massachusetts arboretums stand on this issue? Katy

gardenfan,
here we go again with paul simon's "One Man's Ceiling is Another Man's Floor"!
We have 5 box elders - Acer Negundo- here at the 'retum but none are the straight species. ours are all variega. or aurea types. Winter Lightning, Kelly's Gold, Variega. gn. and wh.; var. gn. and yellow. Love, love LOVE them.The latter 2 are coppiced to keep as shrubs. The others we keep as small trees. A Kelly's Gold that we let get too big- we whacked it to 4' this may to keep it controlled at 12-15'.
so sorry you don't like yours. variegated and aurea plants are usually lest hearty than their straight species parents.
but this is getting off topic now!
best,
mindy
www.cottonarboretum.com/

kt, i'm sorry but i don't know what you are referring to about holding arboreta accountable. ?

anyway, we are not a member of any organization of arboreta.
best,
mindy
www.cottonarboretum.com/

terrene, the definition of invasive you report is quite a bit more generalized than that which is commonly considered by most organizations concerned with the issue and specifically by NISIC. Their definition of an invasive species is any non-native (or alien to the ecosystem under consideration) whose introduction or spread causes or is likely to cause economic or environmental harm. The key words are "economic or environmental harm". Because a non-native plant has an ability to naturalize does not automatically translate into invasiveness or environmental disruption or pose a threat to native flora. Heck, many bulbs and perennials naturalize easily - look at various narcissus for example - and nowhere are they considered "invasive".

It IS a complicated issue and one that bears consideration on all fronts. But as Mindy states upthread, it is very easy to paint with very broad brushstrokes and unilaterally condemn a plant because it is invasive or potentially so in one area but not necessarily anywhere else. Or worse yet, condemn all exotics as potentially invasive simply because of their non-native origins. What IS important is to be aware of those plants that are at issue in your specific area and avoid them if possible.

As always, the better educated we become as gardeners, the better stewards we are for both our immediate and expanded environment. But it doesn't serve anyone to be unnecessarily alarmist or to treat all plants in all areas the same. As the saying goes, the most important thing is location, location, location :-)