This magnificent Albizzia julibrissin aka "Silk tree" was planted in a mere 1" deep bed behind one of the buildings that comprises the Kaiser Permanente HMO complex in Oakland. Many people report it as invasive, but either it is constrained by our dry-summer West, or this unknown species behaves better. As far as I can tell this bed is, or at least once was, irrigated, but in the twenty years we've watched it, there have been no seedlings sprouting up.
We have a lot of them down here, too, and they don't appear to be a problem...so I agree with you that the dry summers must play a role. Even if they were an issue, I'd rather deal with them vs. palm tree seedlings...which are everywhere here.
That one really is a nice specimen.
ecrane3, that's interesting! I have friends in Pleasanton and our CFP firm is in the Concord/WCreek area, so we are out around Hwy 24 and Hwy 580 fairly often. CCC's a big area so I haven't seen most of the residential areas, but I don't think I've seen the Albizzia anywhere I've gone. In Alameda Cty and the western edge of CCC, the El Cerrito/Richmond/El Sobrante area, I've only seen this one and the one that died, on Broadway near the Tunnel.
They are beautiful trees when mature. I wish the PO of our property had planted something really lovely like this, or an evergreen magnolia, instead of the trash silver maple and diseased walnut in our backyard!
If you want to see some, take a little walk on the Iron Horse Trail in San Ramon--there are several of them just north of Alcosta Blvd (I think you could probably see them if you're driving on Alcosta too) and I think there are a few more here & there as you head north on the trail toward Bollinger Canyon. I've seen them in people's yards too but don't remember specific locations off the top of my head, just know I've noticed them.
My sister in law has one in her garden near Chico. They are on farm land and they irrigate in the summer - Albizzia shows up, but, not as bad as they are in the Deep South where they are very invasive. And short lived because of borer pests.
Here in Florida it is Bauhinia that show up everywhere...