JARS v62n2 - The Wild Rhododendrons of Mount Elphinstone

The Wild Rhododendrons of Mount Elphinstone
Ron Knight
Pender Harbour, British Columbia

Rhododendron enthusiasts who enjoy hiking in Oregon and Washington have probably encountered the beautiful Pacific rhododendron, Rhododendron macrophyllum . Although this plant is reasonably common on the West Coast of the United States, it is rare farther north in Canada. In fact, in southwestern British Columbia, there are only four known wild populations. Two of these are found on Vancouver Island and another is in Manning Park on the mainland. The most northerly, and smallest, stand of R. macrophyllum , just recently discovered, is found on Mount Elphinstone on British Columbia's Sunshine Coast.
Rhododendron macrophyllum was named in 1792 by Archibald Menzies who was the doctor and botanist aboard Captain Vancouver's ship when he visited the Pacific Northwest. Menzies called the plant macrophyllum (large leafed) because at the time of its discovery there were no known rhododendrons with bigger leaves. Of course we now know that many Asian rhododendrons exceed macrophyllum in leaf size; however, the Pacific rhododendron at least has the distinction of being the tallest of the West Coast native rhododendrons. It has large, jade-green leaves and twenty or more flowers are held in each dome-shaped truss. These blooms can vary in color on different specimens from various shades of pink to white.
I first learned that macrophyllum grew on the Sunshine Coast from reading an article by Dr. Ben Hall, a geneticist, in the Winter 2006 issue of the ARS Journal. What an exciting revelation that was - a grove of wild rhododendrons within an hour's drive of my home! The article referred to Dr. Hall's DNA studies on macrophyllum flower and leaf bud samples, showing the Mount Elphinstone population to be a distinct genetic variation of the species. Along with small populations in Washington State and Manning Park, these rare rhododendrons, referred to as the Clade 1 type, prefer to live near salt water.
After reading Dr. Hall's article, I was curious to find out how the Mount Elphinstone rhododendrons had been discovered. I learned from Joe and Joanne Ronsley of the Vancouver Chapter that four years ago they had been contacted by a Sunshine Coast environmentalist concerning a stand of pink-flowering rhododendrons on the mountain near her home. She wanted to know if these rhododendrons were wild ones, worthy of protection, or merely escaped garden plants. The Ronsleys invited Steve Hootman, curator of the Rhododendron Species Botanical Garden, to join a mini-expedition to Mount Elphinstone with their environmentalist friend serving as the guide. Once there, they ascertained that the plants were all wild R. macrophyllum and arranged for tissue samples to be sent to Dr. Hall.
All through the winter of 2006, I tried to persuade the same environmentalist to have a member of her group take me to the Mount Elphinstone rhododendron grove when the plants were in bloom. However, after 4 months, 12 emails, 2 meetings, and several phone calls, I realized it wasn't going to happen. The environmentalists were now only willing to guide "outsiders" who were committed to joining their group and helping them further their anti-logging agenda. Since political protest wasn't high on my list of preferred retirement activities, I decided to look elsewhere for a guide and in late May 2006 found a local landscaper who agreed to take me to see the rhododendrons.
On a sunny Sunday in the last week of May, we drove several miles from the main Sunshine Coast highway, along rugged logging roads, until we reached a tiny island of forest totally surrounded by clear-cut. As we walked into the dimly lit grove, I felt as if I had entered an outdoor cathedral. Under my feet was a thick carpet of yellow moss. Far above my head, shafts of sunlight broke through the second growth Douglas fir canopy, spotlighting salal, Oregon grape, and ferns on the forest floor.

Fig 1: R. macrophyllum at Mount Elphinstone
Figure 1. R. macrophyllum at Mount Elphinstone.
Photo by Ron Knight

And then all of a sudden, the rhododendrons appeared in front of me (Fig. 1). They were gigantic - some over 15 feet (5 m) tall, and all in full bloom! Many had side branches that extended an equal distance outwards (Fig. 2). There seemed to be about a dozen individual specimens although it was hard to tell because many had layered new plants from low-growing branches.

Fig 2: R. macrophyllum at Mount Elphinstone
Figure 2. R. macrophyllum at Mount Elphinstone.
Photo by Ron Knight

All of the rhododendrons appeared to be in good health and sported vigorous new growth. Their leaves were glossy green with little insect damage and no indication of fungal disease. Flowering was profuse, with huge light pink blooms appearing on every plant (Fig. 3). In addition, there were some 4-inch (10 cm) tall seedlings growing out of two well-rotted logs that were near the southwest edge of the grove. I spent the next hour taking dozens of photographs.

Fig 3: R. macrophyllum flower at 
Mount Elphinstone
Figure 3. R. macrophyllum flower at Mount Elphinstone.
Photo by Ron Knight

After that visit, I contacted Brian Smart, Planning Forester for the District of Sechelt's Community Forest. He told me that he knew about the Mount Elphinstone rhododendrons and had taken aerial photographs of the grove (Fig. 4). He assured me, "The Community Forest Advisory Committee is excited to have these rare and beautiful rhododendrons within the Community Forest Tenure area. We are looking forward to working with the rhododendron societies to develop a proper protection and management strategy and we are also interested in the idea of assisting with propagating these rhododendrons within the Community Forest area."

Fig 4: Aerial photo of the 
<em>R. macrophyllum</em> site at Mount Elphinstone
Figure 4. An aerial photo of the R. macrophyllum site at Mount Elphinstone.
Photo by Brian Smart

In October 2006, Dean Goard, past-president of the Victoria Rhododendron Society, joined me on Mount Elphinstone to collect seedpods and cuttings. Since then, he and the Victoria Propagators Group have been able to root some of these cuttings and over 100 plants have been grown from seed. They should be ready for transplanting in 2008. Some will be offered to local foresters to be placed in a remote but already-protected forest area on the Sunshine Coast, hopefully to form a satellite macrophyllum population.
Much additional work needs to be done. For example, with a grant from the Community Forest Committee, a path with signage has to be built around the rhododendrons. Although few Sunshine Coast residents, at present, know the location of the grove, tours are planned for local politicians and garden club members, and a marked path will prevent trampling of seedlings.
Rooted cuttings and seedlings need to be distributed to interested ARS chapters and to university horticultural centres for garden testing. The Pacific rhododendron has a reputation for not adapting well to garden environments, but perhaps this Clade 1 variety will be different.
A very contentious debate will be entered into soon by Sunshine Coast politicians: Should the Elphinstone rhododendron grove remain relatively inaccessible and hidden from the general public, or should it be developed and publicized as an environmental education destination?
And in the back of everyone's mind will be the bigger question: How did R. macrophyllum get to Mount Elphinstone in the first place, and are there other undiscovered populations on the Sunshine Coast?
It's time to lace up my hiking boots and find out.

Ron Knight is a past-president of the Vancouver Chapter and currently serves as ARS District 1 Director.