Your question about burls is interesting. We know that they help Manzanitas survive fires, but don’t know anything about them helping to survive life in pots.

In north San Diego County there’s another species of Manzanita, different genus, Xylococcus bicolor (”Mission manzanita”). Not as dramatic as those pictured in this blog, but they do have some of the same features, with leaves that look much more like olives in both color and shape. Attractive red bark, deadwood as well, but not as shimpaku-like as those pictured. I did dig a sizable, mature one one up and I transplanted it in my mother’s garden — same area, same soil (decomposed granite), and it has taken off and grown considerably. Now, that one, like most other chaparral plants, grew from a very large burl that had probably been burnt a few times over the years, and that burl probably had a lot of life in it to keep the plant vital. So it could be that Xylococcus is a viable manzanita. I wonder if any of the collected Arctostapylos had burls to sustain them?