was Monarchs: Eucalyptus.. now is exotics

Richard Worth rworth at oda.state.or.us
Mon Jan 28 12:46:17 EST 2002

Doug wrote:
>The Mediterranian climate of California and all the settlement probably makle
>it less likely to present the magnitude of a problem as in the 'Glades, but
>(please tell me what they are called) rivers in portions of north-central
>California are loaded with some lilac colored weeping willow like ornamental
>from China that is as bad to the last remaining wild riparian places there
>and pestulant as the casurinas, though on a different scale.  I doubt they
>will even be able to put a dent in the relatively smnaller Calif problem.
>And that stupid ornamental was spread from do-gooder gardeners and

Hi Doug and all,
Are you possibly speaking of Buddleia davidii, the famed "Butterfly 
Bush".  I'm not sure of the problem in California, but here in 
Oregon, it is becoming a problem for exactly the reasons you mention. 
I like the plant as much as anyone (have two in the yard) but it may 
be listed as a weed within the next couple of years, and that may not 
be such a bad thing, much to the chagrin of many "do-gooder 
gardeners" ;-).  I had been discussing this issue with our weed 
control supervisor and he was telling me how it was spreading along 
waterways and all around the Portland area.  While I was in the field 
last summer doing work on some other exotic (and toxic) weed,  I ran 
into some Buddleia growing along the Clackamas River and I see now 
what an impact it can have.  It can completely dominate habitat that 
should be filled in by willows, and of course, willows are food for a 
great many lep species, not to mention all the other niches it fills. 
It is no longer remains a bush, growing to tree size on the rock and 
gravel banks of the stream.  It has also been reported outside of 
Eugene and along other drainages of the Cascades.  All the plants 
have the lilac (standard or wild form?) colored blooms.  I'm not sure 
of the fertility of other colors and varieties, but this one is bad. 
While great nectar sources for leps, it really doesn't help them any 
by displacing native plants.  In the long run, people (and all other 
creatures) will be better served by planting natives in landscapes. 
I control any seedlings in my own yard and if the plant is listed, I 
will remove them.

I could go on and on here but will leave it for now.  Thanks for the 
post, Doug.

Cheers,  Rich
(as I watched the snow all day yesterday, I had but one pervasive 
thought.....how can I get on the next plane for the tropics?)

Richard A. Worth
Oregon Department of Agriculture
Plant Division
rworth at oda.state.or.us
(503) 986-6461


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