If you want to try a species of Empress that does not share the invasive attributes of the Tomentosa take a look here. www.worldtreetech.com. They are called Empress Splendors (very well suited name) I purchased a couple of them about 4 years ago and they have been an incredible tree to grow. The flowers that blossom are exquisite! Let me know if you have anymore questions regarding these trees!

They only eat the Catalpa trees. For the past 5 years we've been getting two outbreaks a season and they completely defoliate the tree each time. The trees are quite hardy and bounce back every year. It's not the caterpillars that bother me, it's their frass. It rains down everywhere and I can't keep up with hosing it off. At the end of their caterpillar stage they drop to the ground and burrow underground to pupate. It's kind of nasty to walk in the backyard and have caterpillars drop on your head! lol Unfortunately part of our tree overhangs the deck and the kid's playground equipment. It's just gross. The sphinx moths are pretty cool though. We were going to have the tree removed but for some reason we haven't had any Catalpa worm infestations yet this season. I really do love the tree. The blooms are beautiful, the foliage is attractive, it provides a nice shady place and the kids also love playing with the seed pods which can be huge! I was so happy that the caterpillars didn't make an appearance this spring because I'd hate to cut the tree down but we'll see what happens later this summer and next year. I hope they don't return but I'm not counting on it. Karyn

Invasiveness is ALWAYS depedent on location. What is invasive in one area may very well not be in another, depending on climate, growing season, rainfall amount, winter cold, etc. There are very few plants that are considered invasive uniformly across the country. And this can be expanded to include the argument that it is "only just a matter of time". No, not necessarily :-) Some plants will simply not flourish in any given area because acceptable cultural conditions are not present for them to do so. To my knowledge, Paulownia is not considered invasive anywhere west of the Rockies. The OP should have no concerns about any potential invasive threat in SoCal simply because the cultural conditions are not strongly to that plant's liking. These trees are fairly commonly grown here in the PNW without issue. And even if they did seed a bit, which I have never seen to occur, an argument could be made against its being invasive here, as according to fossil records, Paulownia used to grow here naturally so technically a native :-)) FWIW, many of the plant species that are considered serious invasive problems on the east coast pose little to no invasive threat on the west coast.

Willow acacia pros: Fast-growing. Fragrant blooms, nice foliage, attractive. Tall and narrow, therefore good for tight spots like a side yard. Few pests (it's from Australia). Cons: Roots cannot keep up with canopy, causing wind throw. Fast growth = weak growth; one wind gust can tear the tree apart. Suckering and seedlings. Relatively short-lived (20-30 years). Last year's freeze in Tucson killed almost every Willow Acacia, so they've fallen out of favor here (may not be a problem in your area). Uses more water than natives. We had 2; one lost 3 main limbs during a windstorm and was unsalvageable. The other froze to death last year.