Eucalypts also produce very fine seeds that are easily dispersed by wind and running water. So it is highly unlikey that any Eucalypt will remain confined to your garden.

A resident in the UK, contributing to another forum, was admiring the way that some Australian Eucalypts in an abandoned block of land in London were self seeding so prolifically as to form a lawn. He/she were also considering growing some of these Eucalypts themselves until I pointed out that the fact that seedling lawns were the hallmark of an environmental weed.

Upon my encouragement they contacted officials from DEFA who were immediately alarmed and promised they would asess and monitor the Eucalypt infestation and ban any movement of soil from the site.

Environmental weeds are taken very seriously by well informed government departments even if the average gardener (particularly outside Australia and New Zealand) does not recognize or understand the environmental and economic threats that they pose.

g'day greg,

exactly mate! like exotics from otehr countries that are bought into aus' they have weed capabilities once outside their natural habitat that has natural controls, the euc' is also taking over in madagascar in their forest so their whole habitat in places is turned upside down. but i have heard of the weed capacity of gums in the USofA a long time ago. sometimes in movies you need to look twice to figure out whether the scene is in aus' or not, there are so many gums growing.

also the seed like lots of others can last in the environment waiting for the right conditions to cause germination, that may be over some years?

only just saw your post, don't come here that often anymore.

len

Here is a link that might be useful: lens garden page

Unfortunately yanks seem almost universally hostile to being told that what they are doing is possibly foolish and wrong.

Not sure if it is something about my online personality that rubs them up the wrong way or if it is due to the fact that they arrogantly believe they are superior to all other human beings.

I don't seem to have any where near the same troubles convincing the Brits about my enviromental weed message.

I live near Oakland California, and I for one am delighted to find this discussion! Thank you for your comments. In agreement, Oak trees belong in Oakland, and it is shocking to see the eucs, gasoline trees, being allow to regrow on those very hills after the fire. I stopped in to see if there was information on your devastating fire? I live in the fire zone here, and feel deeply for your losses.

I do agree strongly with you, Greg, on the subject of the tragedy of continued deliberate planting of exotic plants despite them having been shown to be environmental weeds (or should we call them "natives of the future"). It is particularly sad when these plants have no particular virtues which make them better in any way then the natives of the present.
However, I'd have to take issue with the idea that it is a peculiarly American characteristic, to be hostile to being told that planting of environmental weeds is the wrong thing to do. It seems to me that there are plenty of Australians who are exactly the same.
Trish

Taken to its logical conclusion, the prohibition of non-native species would result in massive life-style changes and probable starvation.
For Australians there would be virtually none of the current staple foods -- no beef, no lamb, no potatoes, no apples, almost no citrus etc etc etc.
How many Australians have ever tried bushfoods? - let alone tried to live on them!

That means we shouldn't plant anything not native to our immediate area.
No more red flowering gums in the eastern states!

to the enth degree that's pretty much it philinsydney,

what is needed is we gardeners need to be aware of what exotics we are using in our gardens and their likely hood of spreading into our native habitats.

the gum is also taking over the habitat in madagascar, changing the bio-diversity seemingly forever. and why the yanks haven't erradicated the gum from their environment i just don't understand, i think it is california where it grow like the weed that it is over there. funny though you see pictures on tv etc.,. and you need to take a number of looks to realise you aren't looking at an aussie scene there are so many euc's in shot.

yes greg there is some sort of "no one can tell us" culture with our cousins across the pacific, i meet it regularly on the US side of these forums. one can always put an opposing view without targeting the person, personnaly.

len

Here is a link that might be useful: lens garden page

The tallest tree in Europe? A eucalypt.
The tallest tree in africa? A eucalypt.

http://www.git-forestry.com/KarriKnight-GiantEucalyptusdiversicolor.htm

Citrange raises a good point

I dont think here in Australia we use enough of our BUSHFOODS in everyday cooking

I am continously marvelling my friends with new EXOTIC flavours that are in fact BUSHFOODS

Now with enviro weeds we have natives in OZ that are causing issues in many enviroments Cootamundra Wattle comes to mind as a serious pest

I think, citrange, that there are a few degrees between "avoiding potential environmental weeds" and "the prohibition of non-native species". The second is not necessarily the "logical conclusion" of the first, at all.
However, Australians, who live in a country with a very rich plant diversity of 25,000 native plant species, have introduced a further 27,000 plants from overseas. This does seem to be more than we really needed to keep us from starving!
Many of these plants were introduced purely as garden ornamentals, and their introduction was a superfluous as the introduction of Eucalyptus trees to california - yet the flood tide of incoming plants continues.
We humans are all too ready to convince ourselves that we "need" some beautiful (and cleverly marketed)plant, when we haven't a clue what actually grows naturally in our local area. Perhaps with a bit more knowledge we'd decide that we actually LIKE the place we live in, and that we'd like our gardens to reflect this.
Trish

As regards the planting of non-native or exotics outside their native habitats, this is an age old human custom that spans the globe as well as centuries. I don't think you can suppress the very human desire to grow something different, and people have been spreading plants all over the globe for centuries. It also strikes me as very uninformed to say that all Eucalyptus species planted here in the USA are potential weeds, when it is really less than 10 species that have any chance of becoming pests. Even the two most commonly planted species, Eucalyptus globulus and E. camaldulensis are only localized self-seeders, and can not survive our very long dry season which resembles Western Australia's Perth area, unless they are near the coast where we get summer fogs that mitigate against the 6 month long dry season. The many other Eucalyptus species being grown here are not pests at all, and species such as Eucalyptus citriodora, E. ficifolia,(I know that these are not currently considered true Eucs), are beautiful, drought tolerant and non-invasive exotics that add much character and beauty to urban gardens.

I think it is important to draw distinctions between what horticulture is appropriate to urban situations, versus preserving existing native habitat in-situ. There is no question that Eucalyptus globulus and E. camaldulensis do have potential to out-compete our native California flora in certain situations, and can be a contributing factor in spread of wildfires. To place the blame entirely on Blue gums for the 1991 Oakland Hills fire is to deny that our California native Monterey Pine/Pinus radiata, which is not actually native to the San Francisco Bay Area proper, was just as much a spreader of fire under high wind conditions as the Blue Gums, and builds up just as much duff at ground level which if not removed, also intensifies wildfires. In fact, the intensity of the fire was exacerbated by the dense plantings between houses on steep hillsides of all types of plants and trees, and insufficient thought to provide clear zones around houses and removal of overgrown and dead tree branches to limit the hazard. Among the few trees within the Oakland Hills fire zone that actually tolerate fire and can survive are the Coast Live Oaks/Quercus agrifolia and Coast Redwoods/Sequoia sempervirens, which have thick enough bark and resistant foliage, and were/are native to the area.

I don't think it is germane that Greg seems to feel that Americans don't like being preached to by so-called experts who seem either uninformed of the total picture, and/or selective of the facts they cite, or have a particular agenda in mind. Greg's thinking is very much in line with many native plant enthusiasts here in California, and just as one dimensional in my view. I am all for celebrating one's native flora and any attempts to preserve it in habitat. I think it is rubbish to propose banishing exotic species in urban gardens that are not...

I am no against the use of all exotic plants here in Australia nor in California Bahia, merely agaist their open slather introduction without proper consideration of the long term ecological and economic consequences.

"To place the blame entirely on Blue gums for the 1991 Oakland Hills fire is to deny that our California native Monterey Pine/Pinus radiata, which is not actually native to the San Francisco Bay Area proper, was just as much a spreader of fire under high wind conditions as the Blue Gums, and builds up just as much duff at ground level which if not removed, also intensifies wildfires."

The fact that Pinus radiata is not native to California and equally contributes to bush fires is hardly a credible argument against what I am suggesting. Merely that pinus radiata should not be planted in gardens either.

"this is an age old human custom that spans the globe as well as centuries"
May be so but now we are supposedly scientifically literate enough to recognize mistakes and desist from continuing with them. Or perhaps not in many cases.

Eucalypts from wet sclerophyll forests and flood plains here in Australia can still infest moist gullies and water ways in California and cause major local ecological damage. So again this is not an excuse for continuing to do as you please.

"I think it is important to draw distinctions between what horticulture is appropriate to urban situations, versus preserving existing native habitat in-situ."

Bahia this so clearly demostrate that you do not comprehend that urban environments are part of natural environments and that what happens in urban environments will eventually effect natural environments. There is no 'force field' around your urban environment that prevents seeds spreading out into surrounding natural environments. The fact that many of the plants that you cite do not cause a problem is simply a reflection of the fact that there are plenty of people in urban environments removing Euc seedlings from where they are a nuisance, simply trampling them down or mowing them into oblivion. That is rarely the case in bushland where they are free to grow and spread unchecked.

"Planting exotics in one's garden may actually be better for the natives in habitat, in that you are not polluting the local gene pool"

Now that is one of the most lamest arguments for planting exotics that I have ever come across. So instead of polluting the gene pool of local flora you would rather see it obliterated by invasive garden plants. Come on Bahia, surely you can do better than that.

"Greg's thinking is very much in line with many native plant enthusiasts here in California"

You have given me a ray of hope. So there are people who think like Australian conservationists in California.

There are many Australian native plants that can probably be grown in California and good luck to you with them. But it should not be left up to nursery proprietors and gardeners to...

Like you, Bahia, I'm not against the growing of exotics, provided we are quite sure that they are not going to become environmental weeds. I'm not surprised to hear that some Eucalypts are not environmental weeds in California. These would be the ones that have been planted in conditions that are very different from their home conditions. Australia is a country about the same size as the contiguous states of the USA and has a similarly large range of soils and climates. Some Eucalypt species grow in almost every one of them.
I doubt very much whether all the 1000 or so species have been tried in California yet, and think we can safely bet that there are more environmental weeds yet to be introduced there. There are plenty of good candidates, for instance, from the Perth area.
The trouble with large, fast-growing trees, particularly eucalypts which do indeed coppice well and so can't be killed just by chopping them down, is that the first recognition that they are environmental weeds is normally followed by a long period of angry denial. This is because removal is so expensive and difficult that it's beyond the income and ability of the average garden owner, so it's a lot easier to deny than to do something about the problem.
In an ideal world, those who indroduce exotic plants would be required to demonstrate to a responsible government authority that they have trialled them and can guarantee that they won't become weeds. Where mistakes have been made, nurseries should be made responsible for the removal of the environmental weeds they have sold, TV gardening shows should fund the removal of plants they have recommended but which escape over the garden fence, and so on. In our dreams!
I also worry about gardeners who think that it's OK to put an outsized plant in an urban environment where it fits beautifully so long as itis always kept coppiced. Changing times and human nature ensure that they will get away one day. There are many gigantic camphorlaurel trees here in Toowoomba which were kept as hedges for 80 years before eventually escaping to become rows of monsters.
I wonder how many of the silky oak rootstocks of those popular little grafted grevilleas, which the last few years have seen planted so close to so many houses, will eventually escape from the restrictions imposed by their scions and turn into foundation-destroying, concrete-cracking big trees.
I appreciate the distinction that you make between urban situations and existing native habitats. However, with the current rate of world population growth we can hardly avoid the obvious conclusion that "urban situations" hundreds of miles across are likely to be the world's future. How long, for example, is the Sunshine coast/Brisbane/ Gold Coast conurbation? Longer than that, I think? It's predicted to spread 100 miles west to Toowoomba in the next 50 years. How big are California's suburban sprawls? Is it really OK for them just to gobble up whole ecosystems?
And have you...

I feel that Trish has brought up good points that actually address the statements I made, while many of Greg's points do not. To whit, Pinus radiata trees are native to California, just not the immediate vicinity of the Oakland hills fire zone, and the point I was making is that any tree would have burnt in such a wind driven fire, and Eucalyptus globulus were made a scapegoat for the spread of the fire, when in fact it was due to human ignorance of how fires spread, and proper landscape design to minimize such threats. This hillside fire zone is now once again full of large trees and insufficient clear zones of lower growing, low fuel vegetation, as if the correct lessons about creating defensible space were not learned at all.

Your assertion that polluting the local gene pool with non-local plants is lame, is a very real concern to ecologists here in California, in that we often select native species from areas that are not local or even similar to our local ecotype, on the basis of horticultural characteristics of easy growth, good ornamental appearance, easy propagation. These cultivars may not have suitable characteristics that the locally developed gene pool has developed over generations to cope with the local environment, as well as sustain the synergistic relationships with local fauna. Do you not recognize the fact that this could be damaging to the local gene pool? Planting of natives in urbanized settings is not capable of bringing back the entire ecosystem of inter-related plants and insects, but only plays at bringing back some simplified facsimile. Isn't it then in fact better to try and preserve intact habitats and protect them in situ, rather than place undue emphasis on creating facsimiles that can't possibly replicate fully the real thing? I don't feel it is lame to advocate that planting of appropriate exotics in an urban setting that also provide wildlife and habitat value, are not potentially weedy, and can adapt as well to natural rainfall and weather as our local natives. Greg also conflates the issue of planting exotics in lieu of natives with invasive weedy species. No where did I make any claims to say that it is appropriate to plant exotics that are known to be locally invasive. I am not advocating that one must or should plant exotics, it is certainly anyone's prerogative to prefer their own local natives in their own garden. However, if you are planting cultivars from outside your local area, or using "natives" that are not actually native to your area, in a very real sense you are stirring up the gene pool in perhaps unintentional ways, as a very real risk to the long term sustainability to your locality.

I am very much aware that urban environments are part of the larger environment; the case I was making is that one can not simply return most urban environments to any semblance of what existed before they were created. The best we can do is try to work with the environment to reduce our...

"No where did I make any claims to say that it is appropriate to plant exotics that are known to be locally invasive"

You don't seem to recognize that Australian Eucs are at least locally invasive. I have come across a few sources that say that they are indeed invasive in California. River Red Gums for example can survive quite happily in quite dry areas as long as they are inundated every 10 years or so - likely in many Californian river valleys not to far from the coast.

Bahia your argument about polluting the local gene pool is lame because to prevent it you are arguing for planting of exotic and potentially invasive (locally or wide spread) Australian Eucalypts rather than planting local varieties of local native plant species.

I do recognize that planting non-local varieties of local native plants can be ecologically damaging.

But planting environmental weeds is vastly more damaging and planting even non-local varieties of local native plants may be an improvement.

Does your environmental weed experience extend beyond street scapes and botanical gardens?

Have you spent any time in conservation sector undertaking weed control in bushland?

Probably not. Home gardening provides you with very narrow experience and a very narrow view of conservation. And home gardeners are rarely credible experts in assessing what exotic species are likely to become environmental weeds in the future or indeed which are environmental weeds now!

"here was nothing native growing on my lot when I first started gardening this plot."
Well this mounts a good case that you should be the first to wipe out all the weeds and exotic crap on your block, plant a Californian native garden and provide a toe hold for local species to start re-colonising the weedscape.

It is not a credible reason for you to go on planting exotic and potentially invasive rubbish - including Australian plants.

"My point is that it seems both presumptuous and bit like preaching to insist that all exotics are inappropriate in all situations"
Indicates that the US has a long way to go to catch up to Australia and New Zealand in embracing their own flora and recognizing that home gardeners need to make an effort in preserving it.

There is also the issue of 'sleeper weeds' that is rarely appreciated by home gardeners and the general public.

These are exotic species that are naturalised and form self replicating populations but so far are not causing any major wide spread ecological damage.

All that is required is the right set of environmental circumstances to line up in order to allow the species to 'break out'. Such as a bush fire followed by good rainfall. Once the population reaches a critical mass then it become impossible to control them.

Eucalypts absolutely dominate nearly all Australian landscapes and the Califronian climate is not that disimilar to the climate of semi arid parts of Australia where Eucalypts also dominate the landscapes.

So the potential for Eucs, particularly dryland Eucs, to become major woody weeds in California is clear and present.

And if you can't see that potential Bahia then it is simply a reflection of your lack of ecological experience and narrow garden focus.

"The exotic vegetation that replaces indigenous plant communities in urbanising regions, disassociates us from the rhythms and diversity of the native landscape and a sense of the place; and we are the poorer because of it."

Michael Hough, Professor of Landscape Architecture, York University, Canada

No point in having a conversation with someone who has an agenda which obviates any need to consider facts. Since you so obviously know so much about the state of Eucalytptus species infestation in the USA, which is in your view reason enough to avoid planting any Australian plant elsewhere than Australia because of the grave impacts on our local ecology, I will defer to your expertise and greater wisdom. Oh, by the way, did you neglect to register that I did mention the very species of Eucalyptus, both E. camaldulensis and E. globulus as being amongst the few that have weedy potential here in California? As to any Eucalyptus species ever having a chance in hell of becoming an escaped weed in someplace like Ohio, what is your supporting evidence beyond a Wikipedia citation?

As to presuming that I have no experience with conserving native habitats or the issue of escaped exotics in the wild, you form this conclusion on the basis of what, exactly? Yet you continue to sidestep the very real issue of potential issue of gene pool pollution by mixing of selected "native" cultivars amongst local gene pools, and act as if this is a non-issue to consider. If you are going to walk the walk instead of just talk the talk, then "native" species should only be collected within their naturally occurring habitat for revegetation purposes, rather than planting out man selected cultivars from other parts of the plant's range, and often selected for their ornamental characteristics rather than those qualities that make them a good fit for their particular geographic range.

As well, you failed to address the point I made about how planting out natives in already urbanized settings can not begin to replicate a fully functioning natural environment, the closest you can come is a facsimile, the original diversity of species is impossible to fully replicate. Therefore, as I stated before, it is more important, as well as more useful for the conservation of species diversity, to place more emphasis on preserving intact environments that remain, rather than play at recreating what was, in urban settings which have changed the hydrology, soil structures, sun and shade, etc, etc. Certainly no harm in promoting "native" plants for use in gardens, but to insist that only natives should be used is no more or less valid than other approaches. The only way you would actually convince me otherwise is if you did your homework, got off your soapbox, and addressed the points I raised in a logical manner, rather than resorting to bullying and name calling.

I suppose that we also differ philosophically on the point of gardening and cultivating plants in general. I see landscape design as encompassing various methods with varied purposes. To the point that use of exotics does no harm to the surrounding "wild" landscape, what is wrong with appreciating plants much as an artist uses various paint colors, having a diverse palette to create beautiful effects. If...

"The exotic vegetation that replaces indigenous plant communities in urbanising regions, disassociates us from the rhythms and diversity of the native landscape and a sense of the place; and we are the poorer because of it."

Professor of Landscape Architecture, York University, Canada.

1) I am not talking about Ohio - I am talking about California.

2) You were trying to convince us in your last post that E. camaldulensis and E. globulus would have no hope of being environmental weeds in California, now you concede they could be.

3) "As to presuming that I have no experience with conserving native habitats or the issue of escaped exotics in the wild, you form this conclusion on the basis of what, exactly?"
Because Bahia you talk exactly like the horticultural 'experts' here in Australia, who think they know about environmental weeds but haven't got a bloody clue. E.G. According to them something like Gazania does no harm to the environment and is not invasive compared to me with field experience who sees infestations of Gazania all over the northern suburbs of Melbourne.

4) The issue of pollution of the local gene pool can easily solved by localised indigenous nurseries. It is still not an excuse to plant potentially invasive Aus natives.

5) Perhaps you can't re-create ecosystem exactly as the were before European settlement but you can still certainly re-create valuable habitat for many species of local fauna. Not being able to re-create ecosystems exactly as they were is still not an excuse to plant potentially weedy Aus natives.

6) The only meaningful way to preserve intact ecosystems is to stop people like you from planting weedy exotics, that continually invade them from their urban strongholds, and require enormous resources to keep them out of the intact ecosystems.

Did not your first post respond to some one in Ohio who was wanting to grow Eucalyptus, and you seemed to be saying that even in a place where they are not winter hardy they were an environmental weed? Apparently you don't take the time to actually read replies, as I have said in both of my previous replies that Eucalyptus globulus and E. camaldulensis are amongst the few species that have been able to reseed in the wild. As to whether I talk like your perceived environmental enemies back in Australia, that does not apply to my own experience with exotic weed control here in California, nor can you presume from my views that I advocate planting of known weedy species, nor potentially weedy species. You seem to make the case that any and all exotics are a problem, when centuries of garden experience shows that not all plants will be problems. If you want to make a case that we should close the borders and stop planting plants from other parts of the world, such is your right to do so. I don't think you will convince many people who don't already agree with you, however, as you can't seem to support your case with proper facts and documentation. With the mention of Gazania, and you don't actually say which species, or do you also include sterile hybrids with your broad brush? Gazania is not generally a problem here in California. You also fail to make the case that an exotic plant that does not spread by wind blown seed or berries attractive to birds, and is planted in the middle of a city becomes a threat to wild areas miles away. Even more so if the native climate is such that an exotic can be survive in the wild, nor reproduce successfully because the insects it needs to form seeds are not around, or the rainfall patterns do not support sustained growth beyond germination. Mediterranean climates are very good at eliminating competition from plants from wet summer climates that can't survive our 6 month long dry season.

On the other hand, some desert or Mediterranean climate plants have proven to be difficult weeds here in California and the desert southwest. Species such as Tamarix species have become entrenched weeds in watershed environments, as has Arundo donax, Scotch Broom, Cotaderia jubata, Himalayan Blackberry, etc. All of these are problematic here because they do set prolific seed, or fruit which is attractive to birds, and can survive our climate and successfully reproduce. Plants with similar characteristics would be on any sane person's short list of plants to avoid. Since you seem to imply that I am the type to advocate planting weedy species that continually invade from their urban strongholds, let me go on record that I never plant any of the listed weedy species as indicated by our local native plant society. To include all plants from Australia and seek to keep anyone from enjoying them here in California seems rather extreme, and does not address the real problem species.

You keep failing to address...

"Even the two most commonly planted species, Eucalyptus globulus and E. camaldulensis are only localized self-seeders, and can not survive our very long dry season which resembles Western Australia's Perth area, unless they are near the coast where we get summer fogs that mitigate against the 6 month long dry season"

You are the one that orginally told us that these to Eucs were not wide spread problems in California. Then you seemed to switch to the idea that these two Eucs are the only ones likely to be invasive. Make up your mind Bahia!

"As to any Eucalyptus species ever having a chance in hell of becoming an escaped weed in someplace like Ohio,"

You are the one who brought up Ohio not me. I was refering to California from the beginning.

"You seem to make the case that any and all exotics are a problem, when centuries of garden experience shows that not all plants will be problems."

Oh don't make me laugh Bahia. In Australia alone garden experience by learned horticulturalists has given us thousands of noxious and environmental weeds so far. Oh....plus the relatively few benign exotic species.

The precautionary principal should be used in assuming that all new exotic plants are invasive until sufficient scientific evidence is gathered to prove otherwise.

"Gazania is not generally a problem here in California. You also fail to make the case that an exotic plant that does not spread by wind blown seed or berries attractive to birds, and is planted in the middle of a city becomes a threat to wild areas miles away."
Gazania rignens is clearly not sterile or, if it is, then it has some means of vegetative seed production that its promoters failed to consider.

The pattern of infestations around Melbourne clearly indicate that the seeds are wind dispersed.

I am sure that our Paterson's Curse started off in this way as a many small localised infestations that no one took any notice of. At least until it was blanketing the hills and plains with purple and seriously impacting on agricultural production. But then it was far to late.

"To include all plants from Australia and seek to keep anyone from enjoying them here in California seems rather extreme, and does not address the real problem species. "

Precautionary principal Bahia.

As a native plant dealer in Australia it is my perogative to refuse to sell to you for environmental reasons in the US. I guess it is a case of tough titties.

"Eucalyptus globulus is a host plant for our California Monarch Butterflies in winter"

And how many species of native fauna and flora are excluded or even endangered by local infestations of Eucs and other exotic plants?

And your Monarch Butterflies are clearly not dependant on Euc globulus. Why don't you plant the orginal native host plant instead?

"and thoughtful selection of exotics to avoid potentially invasive species with known capabilities to reproduce in the wild is very much a part of what...

Your biases show rather a bit too obviously, if you are so willing to paint all nurserymen in the same category, and no, I do not grow and sell plants for a living, but I do support nurserymen as a necessary part of my making a living doing landscape design. Your position is so "out there" that it is pointless to continue this discussion any further, but I include a reference to the list of plants considered most invasive here in California, and would like to point out that only Eucalyptus globulus is included in the list.

http://www.cal-ipc.org/ip/management/ipcw/sciname.php

You might find it enlightening to read the info on the entire site, to be able to speak more knowledgeably about invasives in area that you have probably never visited, nor worked in as a professional in the green industry. As I read through the list of plants myself, I was reassured that none were listed that I actually use in my garden designs, although I would hardly presume to say that something, some day might not eventually be a problem. When I do see that something I have planted seems predisposed to volunteer in the garden, I will often remove it and stop using it in gardens.

Rest assured, if you were the only native Australian plant dealer in the world,(and I can assume that you are rather small time in comparison to the Australian native seed companies that do ship worldwide), I would never willingly do any sort of business with you, and suggest you get a life...

"if you are so willing to paint all nurserymen in the same category"
Perhaps not all but a great many!

"and would like to point out that only Eucalyptus globulus is included in the list."
For now! Vinca major has been a well known and major weed around Melbourne for decades and yet it has onlt receently been declared as a noxious weed. Again I also point out the issue of sleeper weeds.

"speak more knowledgeably about invasives in area that you have probably never visited"
I may have never been to California but I do know the ecological behaviour of many Euc species quite well and that native lerp psyllids/possums/mistletoes, that are very important in keeping Eucs in their 'ecological box' here in Australia, are not present in California.

I know more than you are obviously prepared to concede about Eucs and their likely behaviour

"nor worked in as a professional in the green industry"
I work professionally in both the landscaping/nursery sector and in the conservation sector so I am well experienced in 'noticing' the damage that invasive garden plants can do.

"When I do see that something I have planted seems predisposed to volunteer in the garden, I will often remove it and stop using it in gardens."
By the time you do there will be seed in the soil and probably some dispersed outside the garden. Do you follow up 12 months or more later? Do you look in neighbouring gardens or reserves to see if they have spread there as well? A cursory look around the garden bed where you planted them just wont cut it.

"I would never willingly do any sort of business with you, and suggest you get a life..."
Oh well boo hoo my life and business are ruined :-P

The lerp psyllid is already here in California, and has caused extensive damages/losses to E. camaldulensis in particular. It was obvious from your comments that you have no experience with Eucs in California landscapes, and don't actually know the situation here. As to weeds and further follow up, I am actively involved for years after I do the initial design/installation, and have never noticed any ongoing problems with on-going weeds from things I have planted. Again, you are being so overly general about landscape plants being potential weeds, that it makes your tirades rather ludicrous. You also seem to assume that gardening in a Mediterranean climate has close analogies with gardening in a temperate climate such as Victoria state with its year round rainfall, particularly with regard to plants being able to successfully colonize and reseed. If you were from Perth or Albany, and actually dealt with Mediterranean rainfall patterns, you would certainly be more knowledgeable about potential invasive species in this type of climate.

There is a huge difference in successfully promoting the use of native/indigenous plants and encouraging folks to use them, and dictating to gardeners as to what they "should" plant in their own gardens. With your approach, it is obvious you are only preaching to the already converted, and are incapable of doing the actual research to speak knowledgeably about topics which you have no direct experience. I wouldn't presume to try and tell you that all California natives are potential weeds anywhere in Australia, as you have stated about Australian plants outside Australia.

"and have never noticed any ongoing problems with on-going weeds from things I have planted"

Notice being the operative word here!

Being able to notice weed invasion you first have to be able to distinguish native plants from weeds and very few Australians, and I could safely extrapolate to most Amercians since our cultures are so funademantally similar, are caple of distinguishing the vast majority of native plants from noxious weeds.

And you know how I can be so sure of myself Bahia? Because, prior to becoming involved in the conservation sector, I was very much among the ignorant masses who could similarly see nothing particularly wrong with 'natural' landscapes in urbanised regions. Now I am far wiser and more experienced than I was.

"The lerp psyllid is already here in California, and has caused extensive damages/losses to E. camaldulensis in particular. "
Well good for you guys that you have the lerp psyllid over there exerting some level of ecological control over you Eucs. But ecological balance is far more complex than just one insect species.

Do you have Bell Birds over there that actively promote the expansion of lerp psyllid populations? Do you have the native mistletoes? Do you have possums or any arborial mammals that can feed on Euc leaves and flowers.

What if some down stream effect of global warming some how effects the fecundity of lerp psyllid? Do Californian or US ecosystem have backup ecological control vectors?

"Again, you are being so overly general about landscape plants being potential weeds, that it makes your tirades rather ludicrous."
A great deal mor sensible than your tirades that all exotic plants should be trusted until they are proven to be weeds. By which time it is far to late to put such an ecological genie back in its bottle.

"Mediterranean climate has close analogies with gardening in a temperate climate such as Victoria state with its year round rainfall, particularly with regard to plants being able to successfully colonize and reseed."

I may have never visited California but you have clearly never visited Victoria.

Much of Victoria, apart from the southern and eastern flanks of the Great Dividing Range, very much have a Mediterranean like climate. With the ongoing drought in southern Australia that Mediterranean climate has increasingly become a semi-arid climate, and most of our
Euc species are well equipped to survive such prolonged droughts.

Victoria has never had year round rainfall. High winter rainfall with low winter temperatures and neglibable summer rainfall with high temperatures. With the ongoing drought our high winter rainfall, which we relied on to fill our dams, has been replaced by sporadic light showers. Consequently we are in trouble over water with our expanding population and demand and substantially reduced supplies.

"With your approach, it is obvious you are only preaching to the already converted"
Wrong! Increased business is...