JARS v39n2 - Exploring For The Western Azalea In Southern California

Exploring For The Western Azalea In Southern California
Michael A. McCullough, San Jose, CA

For some time I have been an admirer of R. occidentale , the Western Azalea. The Spring 1977 issue of Pacific Horticulture, with an article by Frank Mossman introduced me to Stagecoach Hill. Since June, 1977 I have explored Stagecoach Hill, alone, or with Britt Smith and/or Frank Mossman. I accompanied Gene German on several of his exploring trips to the Flynn Creek and Point Arena Areas of Mendocino County. Not far from where I live can be found the Western Azalea growing in places like Big Basin State Park, Portola State Park, San Mateo County Memorial Park, and Muir Woods.
When I read Carl Deul's article "A Heat Tolerant Form R. occidentale " in Volume 32 Number 1 of the ARS Quarterly Bulletin, I decided to find out about these azaleas. I had previously met Carl Deul, and it was he who introduced me to the Southern California Chapter, which I am now a member. Carl Deul informed me that the Western Azalea could be found in Southern California at Mt. Palomar (Azalea Creek), the area centering around the town of Idyllwild (Bay Tree Springs, Lake Fulmor, the road leading to Black Mountain, and Saunders Meadow), and at Cuyamaca State Park.

In 1980 I conducted my first R. occidentale expedition in Southern California with a trip to Mt. Palomar in San Diego County. Southwest of the Palomar Observatory with its 200" telescope is Palomar Mountain State Park. I asked a Forest Ranger where R. occidentale could be found, and he mentioned the path from Doane Lake to Thunder Springs (where I discovered Palomar 101 to 104) and the area near Chimney Flats (Palomar 105 and 106). In my third expedition in 1982 I also explored the area between Thunder Springs and Chimney Flat along Doane Creek and Chimney Creek and discovered Palomar 303 which has a pink tube and five pink rays extending the length of the flower running down the outside of the middle of the petal. This three foot high plant has been used in crosses with Northern California forms for the ARS Seed Exchange. On my fourth expedition in 1983, while going along the path between Palomar 303 and 106, I discovered Palomar 402 which has six petals instead of the usual five, the upper two having a yellow flare.

Mt. Palomar has more diverse forms of the Western Azalea than I have seen in Southern California, with at least four population groups:
(1) White flowers and 6" long leaves,
(2) Flowers with pink tubes and rays,
(3) Six petals (upper two yellow) and pink tubes, and
(4) White flowers with little or no pink, normal size leaves.
These are all found near the trail from Doane Creek to Chimney Flats, which is less than two miles long and goes from an elevation of about 4,800 to 5,000 ft. At Mt. Palomar, as with other locations R. occidentale is found not far from creeks, with evergreen and deciduous trees providing shelter not far away.
On my fourth expedition I also explored Azalea Creek, but there were few plants in bloom, and those that were had only a few flowers. It looked like the surrounding trees were cutting off too much light.
In July, 1981, I plant hunted in the Idyllwild area in Riverside County and at Rancho Cuyamaca in San Diego County. In the Idyllwild area I discovered six forms in the places mentioned by Carl Deul (Idyllwild 201 to 206), and at Cuyamaca found two forms where Engineers Road crosses Azalea Creek (Cuyamaca 207 and the late blooming 208). It is interesting to note that at each of the three areas there is an "Azalea Creek." The forms on Black Mountain and Engineers Road have elliptic leaves that somewhat resemble R. williamsianum .

On my fourth expedition in 1983, at Cuyamaca, on the Azalea Glen Loop Trail, I discovered Cuyamaca #403 which has faint pink and white candy stripe pattern on the flower, though it is not as vivid as the Northern California forms.
According to Carl Deul, the 19th Century plant explorer William Lobb explored for R. occidentale in the Cuyamaca area. The seed he collected developed into plants which were later used in the development of the Knaphill - Exbury forms of deciduous azalea hybrids.
On my third expedition in June, 1982, I found forms of R. occidentale at Bay Tree Springs, Black Mountain, and Mt. Palomar which have pink tubes and rays (Idyllwild 301 and 302 and Palomar 303). Until this expedition I thought there was no pink color in any form of R. occidentale in Southern California. The pink forms are early blooming and were missed in my previous expeditions which were conducted in early July. As it turned out, Palomar 105, which was discovered when it was way past its peak, does have faint pink lines in the tube that were not noticed until the third expedition when I found this plant at its peak.
In Southern California I have found 4" diameter flowers like the ones I have noticed at Crescent City Flats, Stagecoach Hill, and Flynn Creek, but I have noticed flowers in the two to three inch diameter range which are comparable to the average R. occidentale in Northern and central California. Heights of the plants range from a low of 3 or 4 feet tall to 10 to 15 feet tall.
On June 22, 1984, I started on my most extensive Western Azalea expedition in Southern California. The first stop was Palomar Mountain State Park where the main objective was to pollinate several of my discoveries with the pollen of Northern California forms for the ARS Seed Exchange. The objective was to join the coloration and/or flower size of the Northern California forms with the heat tolerance of the Southern California forms.
On Memorial Day weekend, 1984, I went to Stagecoach Hill and Crescent City Flats where I collected pollen from several Smith-Mossman and Tom Tatum discoveries, and at Flynn Creek in Mendocino County I collected pollen from Gene German's GG6 which has large 4" white flowers. Pollen from the following were collected from Stagecoach Hill and Crescent City Flats:
Stagecoach Hill
SM 237. Large candy stick colored flowers, 16 per truss
SM401. Large deep pink flowers, wide petals with fringed margins.
Stagecoach Pink Blend. A combination of pollen from various plants with pink flowers at Stagecoach Hill.
Crescent City Flats:
SM 12. Cream flowers, deeper yellow flare, many flowers with petaloid stamens.
SM 101. Pale pink flowers.
SM 135. Large flower, pink outside white inside.
SM 140. Pale pink flowers, orange flare may be on two petals. Number of petals varies from 5 to 7. Is listed in the Greer Gardens Catalogue.
TT 813. Pink flowers variegated foliage.
Pollen was also collected from Allen Korth's and Jerry Harris' plants of GG4AK. GG4AK has 70 to 75 mm pink edged white flowers with an orange flare that sometimes spills into the two adjoining petals. Plant was discovered by Allen Korth at the Spurlock (formerly Craig) Ranch South of Point Arena, and was mentioned in an article by Frank Mossman in the ARS Quarterly Bulletin.
At Palomar I pollinated the following forms: Palomar 102 (with GG6), 303 (SM 401, TT81 *3, Pink Blend), 402 (SM 140 and GG4AK).
While heading back to my car after conducting the pollination, I noticed a group of azaleas located between the 303 colony and the 105-106 colony in which the yellow flare spreads to the two adjoining petals. I was too tired to conduct field work in this area, and will do so in 1985 when I shall be concentrating on Mt. Palomar.
I intended also to explore Cuyamaca on the same day that I explored Mt. Palomar, but ran out of time. I decided instead to head to the Idyllwild area where I would be meeting members of the Southern California Chapter on Saturday. I arrived in the Idyllwild area after dark, and not wanting to try the road to the Dark Canyon Campground at night, a road that I haven't traveled before, I slept in the car.
At 6:00 a.m. on Saturday, June 23, I headed to the Dark Canyon Campground, located along the San Jacinto River, where (according to a Forest Ranger I met in my seed collecting trip last fall) is located the largest concentration of the Western Azalea in the Idyllwild area. The campground was full, but I noticed a plant next to the bridge, Idyllwild 502. I set up camp at Fern Basin Campground, then headed to the meeting place at Bay Tree Springs, stopping along the way at Black Mountain and Lake Fulmor, making sure that my plants were labeled. All the plants still had their old plastic labels except for one. They were all given new metal labels. At Bay Tree Springs I was joined by Bill Jenkens and Ted Tassop of the Southern California Chapter.
The large azalea, near the water pipe at Bay Tree Springs, which the Southern California Chapter has been watching for some time, was in full bloom, as was Idyllwild 201. Idyllwild 202, growing in a big granite boulder was not in bloom; but Idyllwild 303, with its pink tube was well past its peak.
We proceeded south on Highway 243 to the Lake Fulmor Picnic Ground where downstream of the dam is located Idyllwild 203 and 204. In a telephone conversation with Carl Deul, he mentioned that seedlings from Lake Fulmor perform better in Los Angeles than other seedlings from the Idyllwild area.
The next stop was Black Mountain where Idyllwild 205 and the pink tubed Idyllwild 302 are located. Many of the plants here have leaves that are roundish like those of R. williamsianum .
North, across the Highway from the Fuller Mill Picnic Ground is a path leading to a waterfall. R. occidentale can be found along the creek. Alone, next to the waterfall, is a plant that I noticed last year. We took photos of it and the plant was later named Idyllwild 502. We had lunch at the Fuller Mill Picnic Ground with R. occidentale in the background.
The final stop of the tour was Dark Canyon. Bill Jenkins, who has explored the deciduous azalea areas of the East Coast said that this area was better than anything he has seen in the East. He was also impressed by the deep yellow flare of what was to be named Idyllwild 502, the azalea I had previously noticed near the bridge. We hiked upstream along the San Jacinto River for quite a distance, then Bill Jenkins and Ted Tassop headed for home.

On Sunday June 24, I conducted further exploration of the Idyllwild area. At Bay Tree Springs Idyllwild 201 was pollinated with SM 12. Measurements were taken of Idyllwild 501 and 502. Idyllwild 502, with many trusses bunched together creating an effect that would probably win first prize in the Azalea Spray Category in a Rhododendron Show, was crossed with SM 135. Idyllwild 501 was crossed with SM 101. I spent the rest of the day exploring Dark Canyon. In heading back to my car, I decided to cut through the campground. Near Space 18 there is a creek heading towards the San Jacinto River. I followed it and found Idyllwild 503 which has faint pastel pink on the tube.

I proceeded back to my camp at Fern Basin and found out that I had the whole campground to myself. At sunset I walked along a fire road heading toward the upper reaches of the San Jacinto River. Returned to camp to get my camera, but the sun was down when I returned. Took timed exposures of the city lights of Hemet and Riverside at f2.8 at 30 sec, 1 min., 2 min., 4 min., 8 min., 16 min., 32 min., and 64 min. while listening to Mahler's Symphony #1. The longer the exposure the better the slide. Used Kodachrome ASA 64 film.
On Monday I proceeded south to Cuyamaca. Original plan was to spend this day in the Idyllwild area, but was unable to do so, since I was unable to explore Cuyamaca on Friday. Before going to Cuyamaca I stopped at the Ranger Station in Idyllwild to get information on the type of weather the Idyllwild area has. A ranger informed me that R. occidentale can also be found near Devil's Slide Trail, south of Idyllwild. That area will be explored later. Devil's Slide is located in the Wilderness Area, and requires a Wilderness Visitor Permit which is available at the Ranger Station.
On the Azalea Loop Trail at Rancho Cuyamaca State Park in San Diego County, most of the plants were past their peak, far different from last year when I explored this area during the same time of the year when everything was at its peak. Cuyamaca 403 was not as pink as it was last year. Pollinated Cuyamaca 403 with GG4AK and Stagecoach Hill Pink Blend. Off of Engineer's Road, there were no flowers on Cuyamaca 207 and the buds had yet to open on Cuyamaca 208.
On Tuesday I ended my trip to Southern California with a bay cruise of Long Beach Harbor where I took photos of ships including the battleship U.S.S. Missouri.
I have been told " R. occidentale can not grow on the East Coast." Is this so? If it is difficult to grow the Western Azalea on the East Coast, are there ways to make it easier? In a telephone conversation with Carl Deul he informed me that East Coast rhododendron growers such as August Kehr and Fred Galle have grown and bloomed the Western Azalea. The fall 1978 - spring 1979 catalog of the Bovees Nursery mentions that R. occidentale is being grown in Pennsylvania and Michigan.
If the Western Azalea is difficult to grow on the East Coast, what could be done to make the growing easier? The Western Azalea is usually found near water. At Stagecoach Hill many springlets can be found; the ground at Crescent City Flats is a bog in many places. In Southern California the Western Azalea is found near streams, usually in a canyon with evergreen or deciduous trees like Ponderosa Pine or Bay Tree growing not far away giving protection. It may seem that R. occidentale , since it grows near water, should be heavily watered in the summer. To prevent root rot, Bovee's Nursery recommends that you plant in a raised bed using a prepared mixture that gives good drainage instead of the original soil. Using a raised bed is important if your soil is like the soil where I live in San Jose, California, and in other places on the San Francisco Peninsula, where the soil is adobe, which is better for building missions than growing rhododendrons. Most of the rhododendron growers on the Peninsula use raised beds instead of planting in the ground. In the Santa Cruz County town of Aptos, at my mother's place the soil is sandy and has good drainage. I have several plants of R. occidentale growing in the Aptos soil to which I have added organic material, mostly bark. It looks like the main point of raised beds is to improve drainage.

In the Idyllwild area Idyllwild 202 is growing out of a granite rock, Idyllwild 501 has its roots under a large boulder, other azaleas can be seen growing among people who live in areas where established plants of R. occidentale have difficulty in growing can grow plants that can adapt to their conditions. I have concentrated on the Southern California azaleas for the ARS Seed Exchange because the temperature range there more nearly matches that of the East. Was it an East Coast hybridizer who put his hybrids out in the environment and selected the ones which survived the best? By growing R. occidentale from seed, there may soon be forms of the Western Azalea which will thrive on the East Coast. For the person who said, "you can not grow R. occidentale on the East Coast" - try it, you will like it.
If you are interested in obtaining plants of R. occidentale they can be obtained from the following sources:
Greer Gardens, 1280 Goodpasture Island Rd., Eugene Oregon 97401. Catalog $2.00
Reds Rhodies, 15920 S.W. Oberst Ln., Sherwood, Oregon 97140. List and culture sheet 25.
The Bovees Nursery, 1737 S.W. Coronado St., Portland, Oregon 97219. Catalog $2.00.
Cutting grown plants of my Southern California discoveries have been distributed to members of ARS Chapters in the Bay Area and the Southern California Chapter. Frank Mossman of Vancouver, Washington, and Bob Standley of Fort Bragg, California, are also growing Southern California forms of the Western Azalea.