Sent E-mail to Unit Editor, Horticulture and Environment, University of Illinois Extension, Champaign County.
"I have read what I could find online re the threat to wetlands of purple loosestrife cultivars located in gardens. I still have some unanswered questions. I do have a background in Science and some research and library research experience.
Could you please provide me with any references involving academic research on purple loosestrife cultivars in garden/horticultural contexts. I'm familiar with situations like the Manitoba work which placed 'Morden Pink' close to wild forms.
What I would specifically like to know about is research on (1) the loss of sterility by purple loosestrife cultivars in gardens and (2) the production and transmission of pollen from purple loosestrife cultivars in gardens.
Alternatively, if you could refer me to someone who could provide such references, I would also be obliged.
Thanking you,"
I'm sure others on this thread are perfectly capable of doing this, but somebody needed to do it.
We'll see where we go.
Sunny
Purple Loosestrife Cultivars
The word "prove" is not used in science? Then what precisely does one do after they formulate a hypothesis??
Science moves at a rapid pace. Citing articles that are over ten years old to prove your point when the research showing that cultivars cross pollinate is more recent, is only telling half the story. You can pick and choose to prove the point you want, but a person of science must find the whole truth in order to formulate an educated opinion. Earlier you cited a source that was an opinion on why certain groups have an ulterior motives to ban loosestrife using outdated information on lead usage.
FWIW, I also have a background in scientific research. I formulated and proved (oops there's that word again) a new theory in population dynamics for migratory waterfowl. In addition I am currently working on a new system to estimate whitetail deer abundance not based on the SAK method. I have worked professionally in wildlife and fisheries management and done extensive native plant restoration work. I've seen and dealt with the repercussions of invasive species on a daily basis.
http://www.ducks.ca/purple/abstracts/abstrct5.html
I don't know. You can read and interpret it anyway you want, but Morden Pink has been proven to not be sterile, and has been proven to crosspollinate. If you read this report it states that hybridization and cross pollination are exacerbating the problem of loosestrife invasion. Just because you don't see it in your garden, doesn't mean it isn't happening.
Reading the above research, does not solve the issue.
Research:
(1) Lindgren & Clay (1993) survey prior research involving artificial
pollination carried out in greenhouses.
(2) Their own research involves pollination obtained by placing the cultivar
'Morden Pink' in wetland areas (along rivers and within a wetland).
Speculation:
The review article by Vick (1992), suggests that (solitary) 'Morden Pink' plants, in gardens, are not safe. The reason suggested is that they can be pollinated by bees (coming into gardens) and hence produce seed. The problem for some of us is that gardeners say their cultivars don't produce seed. I've seen this apparently dismissed, as 'anecdotal' evidence and it is anecdotal. So why not expect there to be research on cultivars in garden to investigate whether they do or they don't produce seed.
(1) Proof:
When you have formulated a hypothesis, you collect data to test it. Collecting data normally involves sampling, so testing the data must be done statistically. The results are therefore given as probabilities, not proofs.
(2) 'Theories' in science are explanations, not proofs.
(2) "the whole truth" - in the context of knowledge - sounds medieval.
(3) Why would you complain that I cite articles over ten years old 'to prove'
a point, when the source you just cited doesn't contain one reference
after 1993? - Kind of a double standard?
Received following reply from Sandra Mason, Horticulture Extension Educator, University of Illinois Extension. (sent May 1: not received until today due to computer problems)
"Hi -----, I'm not aware of anyone doing that specific work. Seems to me we need to move on and not p(l)ant any of the purple loosestrifes. You may want to contact Minnesota Sea Grant they have a lot of info on the subject. http://www.seagrant.umn.edu/ais/purpleloosestrife_info".
This certainly doesn't answer questions some of us have raised. I will attempt to pursue the matter.
E-mailed the Pest Diagnostic Clinic, Laboratory Services Division, University of Guelph, on May 13, with some specific question re the cultivars. Will give the questions with answer(s), when received.
No answer yet.
Will try other places.
Think the main questions is why don't purple looseftrife cultivars seed in gardens. I've had: 'Morden Pink', 'Rosy Gem' and 'Terra Nova' planted very close together for several years, 'Morden Pink', 'Rosy Gem' and Lythrum anceps planted in the same bed for at least four years and 'Morden Pink' and 'Rosy Gem' in the same beds for ten years or more. None of these have lost their self-incompatability and produced seed. I still haven't seen any reports of seeding of cultivars which were only planted in gardens.
Another relevant question seems to be about the possibilty bees or other pollinating insects could carry pollen, with genetic material, to 'wild' purple loosestrife stands in wetlands. Even if this is a substantive concern, it would still seems unnecessary to go after cultivars in gardens with no proximity to wetlands or to any other 'wild' loosestrife stands.
Well, those are 3 different species. Perhaps they don't cross-pollinate each other. If another Lythrum salicaria, Lythrum virgatum, or Lythrum anceps were to arrive nearby, perhaps on another property, then they would presumably lose their apparent sterility.
The problem, as you know, is with Lythrum salicaria and L. virgatum (may be same species) and they don't have (self-incompatability) sterility. These aren't (apparently polyploid) cultivars and wouldn't have been sold as cultivars and hence put in gardens. Anybody who has 'wild' purple loosestrife should be getting rid of it.
One question that arises is: Why is the claimed movement of pollen apparently one way? (viz. from garden to wild and not from wild to garden). Why doesn't 'Morden Pink' do in a garden, what it did when experimentally planted in wetland or wetland-like habitats (given the stated potential for insect pollination).
I think gardeners, who use purple loosestrife cultivars, deserve answers to intelligent questions that arise concerning purple loosestrife cultivars.
I've been observing this thread from a safe distance.
I understand SunnyBorders' interest in scientifically based information. I don't understand the protest vote, though, that "if it doesn't happen in my garden, then it's not bad to have it".
That gives rise to the issue: the plant doesn't appreciate your presence or lack thereof, so when you are no longer around the plant will make do however it is able.
Same with setting an example: if it is in your garden, why can't I have it? So what if I live in/near wetland territory (since my ethics may not align with yours)? I want that phenomenal color, height, form, and persistence. To heck with what others think/do...
Finally, with regard to the seed-setting questions. For being science-based, things are being phrased a little vaguely here. Have you examined each of your individual Lythrum plants for viable seed? Or are your statements about "no seeds produced" based on absence of new seedlings? That would make a difference in what you are saying.
If there was viable seed produced, then the incompatibility/sterility argument is moot. If that hasn't been examined in yours/others gardens, it should be. If there are no seedlings present, that may only mean that conditions for germination are not appropriate in your garden, and to me that is the point that all those opposed to cultivation of Lythrum are making. Just because they are not seeding in there, doesn't mean that those seeds (and others) won't be a problem where conditions are right.
I don't grow Lythrum. I don't know what the seed looks like, nor what exacting requirements it may need to germinate and thrive. I do know what it can do unchecked in wetlands, and that standing water in an interstate median is enough of a home for this plant to take hold in central KY. I'd rather not see it spread further around (home gardens or not) just to satisfy a craving for a vertical pink to purple flowering element. There usually are more than a few similes that can serve any one particular garden design purpose, and there are usually way more native species that home gardeners have never even tried.
Additionally: Non-natives don't contribute much to the local floral/faunal relationships, either. Every native plant does, in some way whether we recognize it or not. That's just one of the bonuses of gardening with more (not strictly all) indigenous species of your local plant community.
I think prudence works every time it's tried.
Acknowledge number of things ViburnumValley says - obviously reasonable, but only his/her opinion.
I would, however, correct/answer several statements;
(1) I would never simply base my opinion on my own garden.
(a) I have a small perennial gardening business and have put in and maintain perennials gardens over ten or so years. I probably perennial garden more intensively than most and keep a close eye on the soil surface (at least early in the growing season).
(b) I know a life long horticulturalist, who knows much more than I do about perennial gardening and his observations, on purple loosestrife cultivars, are the same as mine.
(c) The no-cultivar folk have dismissed claims of sterility, among garden cultivars, as simply 'anedotal'. They've not seen a need to check such reports out.
(2) To say that non-native (plants) don't contribute much to the local fauna, is simply incorrect. Research by the pioneer quantitative ecologist, David Lack, showed that a well-planted garden (the Oxford Botanic Garden) supports about ten times the bird life that equivalent so called natural areas do. North American studies apparently support this. One thing I am quite certain about, the wildlife here uses any useful plants that are available and sometimes choses introduced species/varieties over so-called native ones.
For that matter, in terms of biomes, we live in an area of deciduous temperate forest, but indigenous farmers and particularly immigrant farmers and loggers (etc) massively altered the environment. The large majority of plants we have/use couldn't be woodland plants, because so much of the original woodland is gone.
(3) I don't believe viable seed is the key issue. I think it is whether genetic material can be transferred from cultivars to 'wild' purple loosestrife in any circumstances.
SunnyBorders,
Concerning (2) in your response to ViburnumValley as to the value of native vs. non native
plants to the local wildlife a very interesting and in depth book by Doug Tallamy called Bringing Nature Home discusses how critical native plants are. I would be very interested in your opinion after you read this book.
Make me a "his" - and thank you for acknowledgment of reasonableness. I can sometimes reach that level.
However, SunnyBorders' comments in #2 show me that one mind is pretty much made up (repeat uses of "so called" is a certain bellwether), so further discussion will bear no fruit.
If one believes that gardens composed of non-native exotics are superior in performing the functions of what would be here (if we weren't gardening) - and would do a better job than the plants and co-evolved relationships - then a legion of Doug Tallamys would make no difference.
Knowing the climax forest for a specific area is only one piece of the puzzle, since systems are far more patchy and quilt-like in their arrangement. Certainly a dense temperate deciduous forest supports only a part of the potential flora and fauna, but every time fire disturbs it (or tornadoes, snowstorms, ice storms, bitter cold, severe drought, insect plagues, etc.) that creates gaps/patches for the pioneer species to intrude and successional species to follow. All the edges support another matrix of species, as do water bodies and water corridors. It is not a static homogeneous system, as your lifelong horticulturist (or even Mr. Lack - is that coincidental?) can confirm.
I'm not sure I'd base my arguments on how well the Oxford Botanic Garden supports the systems of Britain. That'd be about a poster child for loss of original systems, due to millenia of disturbance, habitation, and eradication. Next to sowing salt in Carthage, that's about as changed an environment as one could imagine (well, maybe Mt. St. Helens) and not one I'd hope to hold up as an example.
And here I said further debate would be pointless
I agree.
Next time I see a black swallowtail butterfly on dill, I'll remind it, it's on the wrong plant. I'll have to straighten out a whole host of insects and birds.
Amazing ! - You have mentioned the same insect and plant that Tallamy chose to illustrate chapter five, "Why Can't Insects Eat Alien Plants?". It's one of the exceptions that proves the rule. Unlike many alien plant species, dill has some close relatives in America, and a specialized feeder like Papilio polyxenes is able to use the alien dill.
By the same token, the insects being used for biological controls on purple loosestrife are aliens themselves, adapted to eat Lythrum salicaria in their native habitats.
For someone so secure in their belief that Purple loosestrife cultivars are safe, you certainly have an unending need to feel placated that you are correct. Science isn't enough, no one else's opinion is enough. You have gone on and on about how right you are, but here you are still seeimingly trying to convince youself that what you are doing is right by dragging this out so you can say over and over, there is no proof of the danger of cultivars.
I know of numbers of instances of different insects and birds choosing to use non-native plants, in preference to native plants. In all cases the non-native plants are (closely?) related to the native equivalent. I know of several cases where insects prefer a cultivar to the wild form.
I have read that bees strongly favour the alien 'wild' purple loosestrife. I know they certainly favour the presumably equally alien cultivars.
trillium612,
I don't intend to be secure in 'beliefs', or think things are about being personally 'correct' or incorrect.
The wider topic of alien species (claypa) is very important, but it seems appropriate to stay with the thread topic of purple loosestrife, which is complex enough.
It seems clear, to some of us, that there is still reason for disagreement about what to do with purple loosestrife cultivars. I intend to stay on course and keep reading and asking questions of potentially informed people.
Sorry sempervirens didn't see your comment - have not read the book, but have read a few comments by Tallamy.
Like the fact that he says he is not a purist, for instance. Bit alarmed about an emphasis on woody plants (woody plants and biodiversity).
Will certainly read it. Not a quick reader. Be happy to D-mail thoughts on applications of the book to perennial gardening I do. Fun to think.
SunnyBorders,
The Tallamy book is not a quick read, more of a book to read and go back to and review.
Take your time and I'll wait to hear what you think.
I did hear him speak at Lehigh University a few months ago after reading his book and was personally inspired to add many more native plants. Many of the new additions were woodies, shrubs and small trees which have added more dimension to my garden. I think they'll enhance the visual effect of all the perennials.
Sempervirens,
Thanks for reply and warning re time to read. Just read several extracts on-line, not got the book yet.
Think it might be more expansive/interesting (than my previous suggestion re D-mailing) to start a new thread on (problems with?) applying Tallamy's concepts to gardening.
So far - loved the details of insect anatomy, physiology and biochemistry: concerned about some implications of an emphasis on some woody plants:
interested in how it might apply to our area.
Have planted a number of woody shrubs, but recently just seem to be feeding the rabbits. I certainly agree with you that one needs more than herbaceous plants for dimension in a garden.
Have read the Tallamy book, some background materials and taken time to begin to digest it. Very interesting book. Don't see a lot of discussion of it, on-line. Maybe I missed it. Will respond to Sempervivens, on new Tallamy thread. Notice so many interesting issues (large and small), but can only respond to some. Be interested to hear what others have to say about what I noticed and what I missed.
Since this particular thread is about purple loosestrife cultivars, should quickly note what the book says about them; in my opinion, actually nothing. "Many gradeners vigorously oppose the notion that their beloved garden plants can and do escape from cultivation." (p 84).
On the matter of wind-dispersal of seeds. "Some aliens produce so many seeds that the sheer volume of seeds ensures that some will move considerable distances from the parent plant. Purple loosestrife is an excellent example. A single mature plant can release over 2.7 million seeds every year of its long life, Think of the seeds produced in a wetland choked by thousands of purple loosestrife plants!" (p 84)
The point I originally raised is that there appears to be no scientific or other evidence that cultivars of purple loosestrife seed, in gardens. They can be experimentally induced to seed, including by planting them along rivers and in wetlands, around the naturalized species. I still don't believe that it is valid to extrapolate from the experimental results to the cultivars, in gardens. I still believe that it is necessary to investigate the cultivars, in garden settings.
Am still finding no evidence of seeding by the cultivars, in gardens.