is this hardy in pnw?

Where we are in Crescent City and up through Gold Beach, I believe...good in Sunset zone 17 which extends through Brookings, Oregon and, again, I believe to Gold Beach, Oregon.

Not reliably hardy in the Puget Sound area, although it will winter over in a mild winter or if in a protected microclimate. Probably best grown as a container plant and brought in for the winter.

Thank you....

Sunset 17 is a California climate, which includes San Francisco etc. Oregon from Gold Beach south is in California climate-wise. That's why you are finding California Specials in Crescent City. And the native vegetation in the Siskiyou-Klamath region is different from areas north of there, with wild redwood groves ending on the Chetco River, east of Brookings.

Tibouchina is a nuisance plant in Hawaiian cloud forests, where it is likewise not as cold as it is north of the southern Oregon coast.

An intermediate level of mildness extends as far as Coos Bay, the last point where numbers of Cordylines with persisting, large stems are apparent. A no doubt related occurrence is that single digit (F) record lows start at that latitude, with the bottom floor from that point south being in the double digits (for instance 18 F. at Brookings). There's lots of kinds plants that hang on to 15F or even 10F but not much beyond that, if at all.

To be sure enthusiasts up here get various California plants to live for a time, but they aren't well enough suited to become characteristic features, seen repeatedly as big old clumps or tall trees (except for ones like eucalypts that shoot up fast in short periods of time) in front of houses in ordinary locations* where little other serious gardening is going on, and the like.

*Favored Central or South Puget Sound sites at or near the beach can be almost California mild, grow tender plants for years