California’s hidden superbloom is coming to a forest near you
California’s once-a-year wildflower superblooms — hillsides of orange California poppies, carpets of blossoms in the high desert — draw crowds each spring. But few are familiar with the flashy seasonal bloom that erupts in vivid pink in the forested coastal hills of Sonoma and Mendocino counties.
In early May, in time for Mother’s Day, large flower clusters of the native Pacific rhododendron splash color among shady ferns in green glades of redwood, fir and hardwood.
The showstopping blooms grow wild along trails in several North Coast locations in mid spring, notably in the 300-acre Kruse Rhododendron Reserve and at Salt Point State Park, an hour’s drive north of Jenner along Highway 1.
The rose-pink blossoms in the Kruse reserve are the legacy of a wildfire that burned there decades ago. In its natural cycle, fire clears patches of deeply shaded forest, thinning trees and creating openings that allow sunlight to reach the forest floor. Fast-growing understory plants, like the native rhododendron, take advantage and spread into the gaps. The result is a forest studded with woody rhododendron shrubs that, come spring, burst all together into sprays of blooms on branches up to 25 feet.
Kruse has 3 miles of moderate hiking trails through the second-growth redwood and hardwood forest, which also bloom with native orchids, lilies, violets and other wildflowers. The number of rhododendron blooms varies year to year with conditions, and over time as the forest has regrown, the rhododendrons in Kruse are being steadily shaded out. But they still put on a magnificent display.
Rhododendron flowers grow in clusters of five to 15 blossoms, known as tresses, and each branch often carries multiple tresses. Some blossom among the trees at eye level, but to find others along the trail, watch for fallen petals on the ground, then look up to see them arching overhead.
Kruse contains California’s two native species of rhododendron. Both are woody shrubs and heavy bloomers. In addition to the pink Pacific species, local hills host the R. Occidentale, or western azalea, which is white with a yellow throat and highly fragrant. In full bloom, the mass of flowers fills an entire outdoor area with heady perfume.
Rhododendrons have been growing in California for at least 25 million years, fossil records show, but the genus is also wildly successful and widely distributed worldwide. More than 1,300 species are known to grow in places as diverse as China’s forests, Switzerland’s mountains, New Guinea, Nepal and North Carolina.
Those natural specimens come in colors ranging from pale yellow to pure white to flame orange, shades of pinks and vibrant reds, even blue and purple, some with markings on the throat, bi-colored or tinted petal fringes, with flowers as wide as a hand or small as straws. Some bloom early, in April, while others bloom late into the summer. But the time to see the most is usually the first two weeks of May.
Nursery and legacy collection
Those who want to see cultivated and wild rhododendron blooms in more accessible conditions can visit Hidden Forest Nursery in Sebastopol. There, Mike Boss is literally surrounded by acres of rhododendrons in his nursery, formerly a multi-acre collection known as the Sonoma Horticultural Gardens. In addition to lath houses with potted rhododendrons, azaleas and camellias, Hidden Forest spreads out into a natural canyon under a canopy of trees, with wandering paths along a creek and a reflecting pond.
Hundreds of varieties of spectacularly blooming rhododendrons, many collected and cultivated for decades by the previous owners, open from April to June, depending on the variety. By design, the setting has an almost wild feel, with birds and wooded trails, vibrant overhanging blossoms and color-lined paths.
Boss stepped in to buy the legacy collection and business just before the land was sold for a planned development. He said it’s been a labor of love to restore and care for the 50-year-old nursery. He’s a certified permaculturist and owned a landscape business before taking on Hidden Forest.
Today, he runs one of the few independent rhododendron nurseries left in the state. Collectors visit from around California and even abroad. Among the staff, Armando Garcia, who has cared for the varieties in the gardens for more than 30 years, has an expert’s knowledge of each kind and where they’re located around the 7 acres.
A number of the rhododendron plantings in Hidden Forest are massed together, creating multicolored and multitiered blooming displays beneath branching trees that provide essential shade.