And I'm glad that Paulownia is not YET invasive in the PNW. But it might be one day.

It took 80 years for japanese honeysuckle to become invasive in the southeast. Once it did, there was no stopping it.

So do I read you correctly. We shouldn't grow anything that has
proven to be invasive somewhere in the world and after at least
a life time without causing a problem? Seems overly cautious.

I have none but have been researching them with much interest since learning of former President Jimmy Carter growing acreage of them for harvest as a fast growing sustainable lumber. Seems to be a growing industry.

Well I think the phrase "somewhere in the world" is a bit broad. But if it has proven to be invasive somewhere in a reasonably sized region (in this case, the US), then I think we should be cautious.

Look at Kudzu. It is now invasive in New York after moving through the South. Tree of Heaven has also proved to a wide-ranging invasive. Garlic mustard is now moving into the upper areas of Georgia after being a horrible invasive in northern states.

When plants spring up on their own in a new place (it sounds like this wasn't planted there), that should sound the alarm for invasive potential.

My main point is don't rule out future invasiveness just because none exists now.

And unfortunately this "philosophy" doesn't even begin to stop anyone from doing anything. It's mostly just people talking, hoping someone will listen. Nobody's making any laws against plants like Paulownia as far as I know. So your ability to grow these things in Texas is safe.

For the time being!
Fortunately the economic downturn may stifle passage for a while longer.

http://www.petproductnews.com/headlines/2011/01/12/texas-updates-white -list-of-aquatic-plants.aspx

One of my trees also seeded into the yard across the street one year, they have an automatic irrigation system. Several came up together in a small area of exposed soil, and got weeded out.

The usual one here is P. tomentosa 'Lilacina'. Photos of flowers at Esh's link show that one also. The typical species produces darker, spotted flowers.

The one Japanese honeysuckle I have seen growing on its own here was in a warm, moist pocket facing south, at the bottom of a tree-covered slope on the north end of a lake. Not very big, maybe a few yards across, if that, and no sign of it escaping its special little spot.

While the PNW is certainly conducive to the growth of a great many different plants - there are arguments that a zone 8 climate is best suited to the widest range of plants - we tend to have significantly fewer invasive issues than do areas like the east coast, southeast and parts of the midwest. Simply because our climate is so distinct.

It is always important to check local authorities for invasive concerns in your area. As with real estate, location, location, location is the overriding concern with regards to invasiveness.

FataMorgana

"we tend to have significantly fewer invasive issues than do areas like the east coast, southeast and parts of the midwest."

I wouldn't say fewer, just different, yet many are the same.

The only barrier to a plant's expansion across this country is any regulations prohibiting its transport....and even that is a dubious control, especially with folks transporting a treasure from granny's garden to a new home across the country, Not to mention mail order nurseries or the widespread garden trades and exchanges, like what occurs here on GW. Fortunately, to a very large extent, unbounded proliferation of invasive species is moderately well controlled by Ma Nature. If the setting/climate/growing conditions are not suitable, the plant won't thrive or will be unable to reproduce.