Every invasive exotic (non-native) species has a story of how it got here.
Blue gum and red gum were imported to produce the timber needed for railroad ties. Many annual specie were forage crops for grazing cattle. Some got here by stowing away as seed on or inside cattle or other animals. Supposedly, mustard seed was broadcast by those traveling on the El Camino Real so that other travelers could find the route later. Then there are all sorts of invasive exotics that were imported simply because people liked to grow them in their gardens.
It is difficult to imagine why anyone would import any of the weedy specie of broom (Genista specie) or the sloppy species of pampas grass (Cortaderia jubata). It might have made sense at the time, before more appealing specie were introduced, or before less invasive modern cultivars were developed. Black locust has always been, and continues to be a pretty tree, long after more colorful and less invasive cultivars were developed. They were brought to California by prospectors from the East at a time when no one knew or cared how invasive they would be.
Acacia dealbata was likewise imported simply because it is a pretty tree, before anyone knew how it could naturalize and displace native vegetation and wildlife. Now it grows very rampantly in utility easements where other vegetation has been eradicated. Not only does it interfere with the efficiency of utility cables, but it is also combustible if ignited by sparks from electrical cables. Yet, it is so colorful and pretty in the middle of winter that it is not easy to dislike. Unfortunately, environmentalism is not what it used to be, and some so called environmentalists want it to be protected simply because it is ‘alive’.
Tony Tomeo 
Oh, you have C. jubata too, here we have our own native Cortaderia and jubata has crossed with it. Somehow the environment has to be reclaimed from the misinformed, I too have met the ‘but it’s alive’, well since are smallpox and anthrax.
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That is the same logic I get with the stoners who must remind me that marijuana is a plant (as if a horticulturist must be reminded of that). (They are the same sort who want to outlaw tobacco because second hand smoke is toxic, and ‘big tobacco’ must be taken down.) Anyway, I want to remind them that poison hemlock is a plant too.
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Is this the acacia that seems to be loved in the Mediterranean area for being a herald of spring? ‘Mimosa’
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Yes. Someone in France had mentioned it. I inquired about it because the pictures seemed to be the same. She made the same sorts of observations about it that I do, and described the fragrance quite well. I happen to like it, as many do, but it really does smell something like an oil field.
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Yes this is the same mimosa which is so invasive in the south of France. It began as an imported ornamental in Cannes. They love it though and have a mimosa carnival every year. It smells wonderful.
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I like the fragrance too, but many do not.
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It’s the association for me. It reminds me of the south of France and sunshine.
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It reminds me of San Luis Obispo, which is why I like it.
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First of all, specie is the plural of species? Eek, that’s so embarrassing. Secondly, yes, I’m familiar with those who object to removal of even the most noxious invasives – Tree of Heaven, Buckthorn, Mulberry – these are the true natives of our new environment, don’t you know. They give me a headache.
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‘Specie’ is plural for singular ‘species’. However, it is so commonly spelled like an American English word that it has become acceptable to spell it as ‘specie’ for singular and ‘species’ for plural. Other Latin words with different suffixes do not work quite the same way. For example, Eucalyptus and eucalypti are somewhat more obvious.
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The conundrums. We recently bought a house on half acre with 1950-era overgrown and ill-planted shrubs and trees. I hate arborvitae. The crab apple had rotted base. So much had been planted right against the house – I wanted wider sidewalks and deeper beds around the home. So chop we did. Until lastly faced with the big sprawling American Chestnut. Beautiful but … Dirtiest tree on earth. Huge thorny pods pounding the roof, rotting across the yard. Grass wouldn’t grow. Dulled the mower blades. Two men from The Chestnut Society begged us to not cut, insisted it was so old. But we brought it down. The crows stayed. The squirrels stayed. Grass grew. Still, SO much guilt.
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OH! An American chestnut! All the chestnuts are rare here, even though there had once been a small section of chestnut orchard at the farm. I intend to eventually get a pair of American chestnut trees because they actually do somewhat well here.
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And of course you must mention that the Acacia or wattle as we call it, is our national floral emblem over here in Australia. Nothing prettier, in my opinion than the outback aglow with yellow in spring.
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Ooops! Perhaps I should have been more tactful with what I wrote. I happen to like many of the acacias, and I actually like the bloom of the Acacia dealbata. However, I also know that it is a serious weed here. Acacia melanoxylon is not as invasive, but it is an odd tree that I do not understand. The flowers are not very pretty, and even the tree is not much to look at. By the time the trunk and limbs get big enough to look handsome, they start to deteriorate. Bailey acacia could be more popular here than it is. It really does well on its own, without becoming invasive. Sydney golden wattle is one of my favorites for bloom.
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I’ve recently planted a wattle in the garden and at the moment the grasshoppers are making a meal of it ☹️
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Those must be some hungry grasshoppers. Not much east acacias here. Our grasshoppers have not developed a craving for them yet.
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Wattle are serious invaders in South Africa. They were originally planted to stabilize the sand dunes around the coast but soon began taking over.
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Yes, they almost always start with good intentions.
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Reblogged this on Tony Tomeo and commented:
Perhaps this recycled article should have been scheduled for the ‘Horridculture’ theme on Wednesday.
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Here in France it thrives in the Mediterranean basin but also now in the north of France because of the global warming. The downside is that pruning is not recommended so it grows very quickly and can easily break and become dangerous. Advantage for us in North, the winter frosts slow it down … Mine is about 4m tall (13ft)
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Yes, they do not respond well to pruning; which is not good for a tree that is so unstable and structural deficient. I generally cut them down completely, so am not concerned with pruning them.
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