JARS v47n3 - Raising Rhododendrons Among the Redwoods

Raising Rhododendrons Among the Redwoods
Deborah R. Upshaw
Eureka, California

Nestled amidst thousand-year-old redwoods, rhododendrons thrive in the cool, misty climate of northern California. Nurserywoman Catherine Weeks takes full advantage of this fact.
For more than 30 years, Weeks has been raising rhododendrons at Westgate Gardens and Nursery located on the outskirts of Eureka, just a few miles from the Pacific Ocean. Spread out over 2.6 acres, this is one of California's most comprehensive display gardens of rhododendrons and azaleas.
Catherine Weeks singlehandedly manages 1,300 different rhododendrons-hybrids and species, and hundreds of distinct azaleas (evergreen and deciduous). "I didn't start with rhododendrons, however," Weeks recalls, looking back three decades. "I began with roses. I had dozens of hybrid teas and floribundas, but then I sadly watched the deer repeatedly come and eat them."
Aware of the native rhododendrons ( R. macrophyllum ) that grew in Humboldt County, Weeks decided to change the focus of her nursery business to rhododendrons. Her inventory increased as she made trips north to Oregon and Washington where she obtained stock from avid breeders and nurserymen.
By propagation (cuttings, layering, grafting) and direct purchasing, Weeks' collection expanded rapidly. Weeks learned a lot by trial and error - especially with regard to propagating through cuttings.
"The system that worked for me consisted of using various strengths of hormones with heating coils underneath planter boxes. Overhead, I set up an intermittent mist of water to come on automatically every five minutes. Some took four weeks to root, while others took as long as six months. The R. Loderi hybrids were some of the hardest to root," she says.
Weeks took an early interest in the large-leafed rhododendrons or those with unusual indumentum, like the compact R. yakushimanum - among her favorites!
Surprisingly, some like R. praestans and R. macabeanum , took many years to bloom. "I've had R. praestans almost 30 years; it's over 6 feet tall yet it didn't bloom until last year. The blossoms are a clear, vibrant yellow with a purple blotch in the throat.
"Thirty-year old R. macabeanum bloomed for the first time last year. It has long, 1 foot leaves with a grayish-white wooly indumentum," she says.
Some of the others she favors are the white to pale pink R. roxieanum - a smaller species with a beautiful reddish buff indumentum. "Slower growing R. recurvoides has reached only 3 feet in 15 years that I've had it. The very reddish, fuzzy foliage compliments the rosy pink to white flowers," she says.
Rhododendron fortunei is one of the finest shrubs on display, combining magnificent foliage with fragrance. "The leaves are nearly a foot long with striking silvery white hairs on the underside. The pink, lilac, or white blossoms are waxy and heavily scented," she explains.
Other fragrant species that Weeks grows are R. lindleyi , R. odoriferum and R. manipurense - plants that flourish in the temperate coastal climate of Eureka, but which necessitate a greenhouse environment where the winters are severe.

"Rhododendron manipurense has very full, crested, glossy foliage, and fragrant, white trumpet shaped flowers," she says. Strongly scented, white R. odoriferum blooms by age 3, according to Weeks. It's a medium shrub, reaching a height of about 10 feet in 30 years.
"We had the coldest winter in 100 years in 1990 and many of these plants were severely damaged, but it didn't kill them," Weeks explains. "Other species like R. lindleyi , R. taggianum , and R. dalhousiae , were burned severely, but are coming back from the roots."
The California garden also features an expansive collection of dwarf rhododendrons like the pastel yellow R. hanceanum , with its delicate 1-inch oblong leaves. The creamy white R. keiskei has thrived in her garden for over 20 years, but still measures under a foot. "The more unusual, purplish-blue R. impeditum has an herb like fragrance. It's a heavy bloomer but it rarely grows higher than 18", she says.
"The big ones are here, too," says Catherine Weeks, referring to her R. Loderi hybrids, "My 30-year-old R. 'Loderi King George' is 25 feet in width and height." The hundreds of hybrids on display at Westgate Gardens and Nursery are as much of an attraction as the species plants.

A dedicated hybridizer herself, Weeks has several hybrids registered with the ARS. Weeks looks for fragrance, color and foliage quality when deciding what she wants to cross. Rhododendron 'Cougar' (her son Melvin's nickname) was the first one she registered with the ARS. It's a R. 'Loderi' x R. fortunei , very fragrant with deep pink trusses, and maintains its color all season.
Rhododendron 'Angel Wings' took 13 years to bloom from seed but was worth waiting for. "I named it 'Angel Wings' because of the way the blossoms twist and fold inside. The large blossoms are sweetly scented. They open a shell pink and quickly fade to pure white," Weeks says.
In 1992 the Weeks registered R. 'Arthur Charles', a hot pink, medium shrub with beautiful dark leaves whose underside are brilliant cinnamon-red. "This is a R. 'Gills Crimson' x R. 'Sir Charles Lemon,' says Weeks, "and there's still some debate about R. 'Sir Charles Lemon', whether it could have been a natural hybrid or a selected form of R. arboreum ."
Weeks has also crossed azaleas. "I have R. canescens , R. canadense , and R. calendulaceum . I crossed them with all colors of the R. occidentale (native of the Pacific Northwest) with wonderful results."
She keeps meticulous records of the hybridizing she's done over the past 30 years-essential information for those she plans to register with the ARS. "Of course, there could be thousands of seeds in one pod, and you can't raise that many seeds," Weeks points out. "It's impossible."
There are over 500 seedlings at Westgate Gardens and Nursery, all hand crossed and conscientiously attended to in spacious greenhouses. Some are inches high. Others grow in 1 and 5-gallon containers.
Over the years Weeks has compiled an outstanding photographic record of the hybrids and species plants she raises. She has over 5,000 transparencies in her files, and her husband, Melvin Weeks, Sr., says it takes about a week to sit through a slide show.
Past president of the ARS, Eureka Chapter, Catherine Weeks initiated a perpetual silver cup trophy which passes to a different member each year. "It can be kept permanently only by a member who wins the best of show award for three consecutive years," she explains. The best of show award has been repeatedly presented to the California nurserywoman, and numerous trophies, silver trays and plaques are displayed in her home.
Weeks raises a large selection of acid loving companion plants that thrive in the temperate climate of northern California. Visitors will see over 100 varieties of Japanese maples, magnolia, eucryphia, crinodendron, stewartia, pieris, mountain laurel, dogwood, michelia, and many others. But with a show of color beginning as early as December and going clear into June, none can compete with the magnificent beauty of the rhododendrons and azaleas at Westgate Gardens and Nursery.

Freelance writer and photographer Deborah R. Upshaw writes for national and regional publications on a variety of subjects such as gardening, parenting, woodworking, arts and crafts, and food.