Ask Mr. Smarty Plants

Before we answer your question, let us tell you what we know about the tree. It is variously called "Royal Empress," "Royal paulownia" and "Princess Tree." It is called a lot of other things by people who either inherited this tree in their yards, bought and planted one, or had one planted by seedlings. However, this is a family website and we can't repeat those things. 

Begin by reading, from the Plant Conservation Alliance's Alien Plant Working Group Least Wanted : Royal Paulownia - Princess Tree - Royal Empress Tree - Paulownia tomentosa.

We would also like for you to read the comments on this Dave's Garden forum site on Paulownia tomentosa, in particular, the 7 negative comments. Notice the comments about it showing up in disturbed ground, and about the roots breaking up foundations, just from a seed that caught on the corner of that foundation and grew into a tree. Considering this tree is purported to grow 8 ft. a year, and that most trees have root system circumferences of 2 to 3 times the height of a tree, we would say your sidewalks, house foundation and maybe the next-door neighbor's foundations are all at risk. If you do plant it, and let it go to seed, you will not be popular in your neighborhood or area for bringing it in.

Our take on this is that you should not introduce this non-native invasive plant to your landscape or anyone else's. We understand that, as it gets older, it looks pretty ugly, and has spread a lot of seedlings all over the yard, neighborhood, state. It is very difficult to get rid of. The best way we know of to get rid of it is don't plant it!