Calocedrus decurrens, or incense-cedar, has broad habitat requirements. Within its range from Oregon to Baja California, it is most often found in hot and dry sites with poor soils. However, the tallest individuals typically occur in “sunny, well-watered sites such as riparian areas in canyons or near subalpine lakeshores“.
In addition to a range of soil types (occurring in everything from ultramafic to limestone-derived soils) and water regimes, incense-cedar is also tolerant of a wide range of temperatures and snow cover; it is rated as cold-hardy to between -17.7°C and -12.2°C (USDA hardiness zone 7). The wide habitat envelope does not translate into ecological dominance; it is extremely rare to find forests where Calocedrus decurrens is the sole or dominant species. Most often, it is found:
In mixed conifer forest with Pinus jeffreyi, Pinus ponderosa, Pinus lambertiana, Pinus monticola, Abies concolor, Abies grandis, Abies magnifica, and Pseudotsuga menziesii, locally with Sequoiadendron giganteum, Chamaecyparis lawsoniana, Tsuga heterophylla or Thuja plicata, and in drier southern sites with Pinus coulteri and Pseudotsuga macrocarpa.
(see Calocedrus decurrens via the IUCN Red List)
That noted, this photograph was taken near one of the few sites where near-pure stands are known, Red Buttes Wilderness‘s Cedar Basin.
For those curious about the lighting in today’s photograph (and the close-up crop of the image), this was taken on a smoke-filled day in late August of 2017. The nearest wildfires were within miles as the crow flies; in fact, we had to use an alternative route to access this area due to road closures. Fortunately, we had the experienced author and naturalist Michael Kauffmann as our guide.
2 specimens of this species from seed collected in Shasta Co., CA, have been reliably winter hardy in the Holden Arboretum (ne OH) in Zone 5 since they were planted in 1995, reaching heights of 25 and 30 feet after 20 years. They have experienced winter lows of -18º F without injury.
Beautiful photograph!
There’s also one in the Halifax Public Gardens. It’s in a spot that’s far too shady & dry so it’s not the best specimen. Nevertheless I have never seen it damaged in our Zone 6b winters despite the wild temperature swings and the record cold (one night to -13F) year of 1994.
I’ve seen some extraordinary and very narrow fastgiate forms in the Portland, Oregon area but alas they failed to root.
My neighbor down the street outside of Scappoose, Oregon has several along the street frontage of their property that have fleck gold varigation, to great effect.
There are specimens in the University of Idaho’s Shattuck Arboretum that were planted in the early 1900’s ( I would have a better date if I were in my office) that survived the winter of 1968 when temps were -48 F for three nights. The trees have produced several naturalized seedlings of various ages/sizes.
Beautiful photographs of an interesting subject, Daniel. Thank you for explaining about the light – once you mentioned the smoke I recognized that characteristic blue haze in the background and the softer, warmer light in the foreground.
Thanks for all the comments regarding hardiness. I suspected that would be the case (that it is hardier than what is published on some sites).
It is curious to me that the species doesn’t have a larger range, given its wide ecological envelope.
Wow! Great photos! I remember from my earliest childhood the distinctive aroma of incense cedar. Although I grew up in Vancouver, my mother grew up, and my maternal grandparents lived in, Plumas County California, where we sometimes visited for summer and Christmas holidays. In that area, Calocedrus is just one of a set of wonderfully aromatic conifers that includes Abies magnifica, Pinus ponderosa, Pinus lambertiana, Pseudotsuga menziesii and Juniperus occidentalis. Incense cedar stands out for me, mostly because of the pencils that were supplied to primary and elementary school children in Vancouver. But let me quote from the mobile app, Vancouver Trees:
Comparatively near Vancouver B.C. in northwest WA state there is a spontaneous pure grove of incense cedar on a west-facing rock covered embankment immediately east of and above Interstate 5, near what I think of as downtown Mount Vernon. (For anybody that knows where the Skagit Valley Food Co-op is, the trees are visible from the northeast part of their parking area). Larger, presumably intentionally planted examples are present on the property immediately behind the slope. And are also presumably the seed source for the grove.
This same combination of “naturalized” incense cedars in dry sunny areas near plantings of them is reported by A. L. Jacobson in his 2008 book Wild Plants of Greater Seattle – Second Edition for locations there.
The Halifax tree was likely planted in the 1920-1940s.
john