Originally Posted by Ian
A few cold hardy arbutus prospects include:
A. menziesii collected east of Packwood, Washington where it grows at an altitude of 2,500' in the Cascade Mts.
A. xalapensis var. texana collected in the Guadalupe Mts where temperatures may drop to about -28C
Maybe A. arizonica collected high in the Chiricahua or Catalina Mts. of Arizona.
The latter two would also adapt well to a climate with lots of summer water. And A. xalapensis can grow on high pH soils (it does in the wild).
They grow on clay soil here as well... and even in areas of very high preciptiation as long as it dries out in the summer.
This is a bit of an observation. In my former neck of the woods in So-Cal the Pacific Madrone (Arbutus menziesii) was never a part of our environment and years ago I failed at trying to grow them, though "Tree of Life Nursey" of San Juan Capistrano and "Las Pilitas Nursey" of Escondido do sell them now.
I spent many early years exploring the Huachuca and Chiracahua Mtns and found the Arizona Madrone (Arbutus arizonica) to be a possible replcement experiment for the San Jacinto Mountains above Palm Springs. Needless to say I never got around to trying out that idea either. However I did run across some personal webpages within the University of Texas website of a Bob Harms (Research Affiliate and Webmaster)
and his personal learning, struggles and successes in dealing with the Texas Madrone on his own acreage. Anyway, perhaps some similiar applications will be of beneficial resource for folks here.
Texas Madrone, Arbutus xalapensis, by Bob Harms ( University of Texas at Austin )
Here is the sites main page which is a plant resource.
University of Texas - Plant Resource Center
Bottomline, take it as an area of resource and practical applications that may be of benefit to your Pacific Northwest. Sometimes reading and learning about newer unique techniques, though from an entirely different area just may trigger some other ideas for personal applications in the Pacific Northwest and beyond.