After the storms: UC Botanical Garden’s rescue operation to save a paradise lost

Decades of tender care built the UC Botanical Garden’s Asian collection, a premier compilation of some of the world’s most precious plants.

Then, in just an instant, a toppled giant redwood tree turned the delicate botanical gem into a disaster zone.

Experts are now converging on the storm-damaged site, perched high in the hills above the UC Berkeley campus to pull bruised and battered plants from the wreckage in a race to save what remains.

“I dig through the debris to find where the plant is located and what is salvageable from it,” said propagator Susan Malisch. Some plants get remedial pruning. Others are rushed back to the garden’s nursery, where cuttings can create a new generation to replicate what was lost.

The historic garden, as well as other arboretums in the Bay Area, were deluged by a barrage of heavy storms this winter, culminating in a powerful “bomb cyclone” on March 21 that delivered fierce winds and pounding rains to already saturated soils. The UC garden’s toppled redwood badly damaged about 57 plants, such as Boehmeria japonica and Leucothoe grayana, collected from Japan’s main island of Honshu; Lobelia nummularia, from the Philippines; Rhododendron argipeplum, from northeastern India; and Pieris formosa from Bhutan.

“Our job is to make sure this collection survives, in perpetuity,” said Andrew Doran, the Garden’s Director of Collections, above the buzz of chainsaws. “These plants came from the wild. They’re very, very difficult to obtain again.”

With its winding paths, blossoming bushes and stands of towering bamboo, the Asian garden is not just a special botanical collection. It is also a research project, rich in scientific value — and a place of serene beauty.

The Asian collection is one of the oldest parts of the garden, with plants collected in the early 1900s from Scottish explorer George Forrest’s and Austrian-American botanist Joseph Rock’s expedition to western China and Tibet. Information about each plant in the garden is entered into a computer database under its “accession number,” which identifies when and where it was collected and by whom.

“That’s really what separates us out from a lot of other botanical gardens,” Doran said. “If you’re a plant and you want to get in this garden, you have to come with good provenance.”

Doran was at his desk on the afternoon of the March storm when he heard a sickening thud. “The radio sprung to life,” he recalled, as worried staffers exchanged reports. “We all know what a falling tree sounds like.”

Grabbing a hat and umbrella, he stepped out into the storm. Gone was part of a giant redwood tree that predated the garden, planted when the property was just a dairy farm. When it fell, it struck a large buckeye tree. Both historic trees landed in the Asian collection and shattered.

“They scored a direct hit,” he said. ‘It was a sea of branches and debris.”

In addition to the Asian section, there was damage to one of three large endangered spruces from Central America; the top half of the garden’s only Parana pine tree, a critically endangered species from Brazil; a prized eucalyptus from Australia’s Queensland region; and a gum-leaf cone bush from southern Africa. Cascading water carved deep trenches in the gravel paths in the redwood section, the romantic site of many weddings.

Other gardens also report losses. At the UC Santa Cruz Arboretum and Botanic Garden, a mature and unique Himalayan Cypress was shattered.

“It didn’t just fall over. It blew apart in pieces,” said Martin Quigley, director of the UCSC garden, which also sustained damage to its growing and nursery structures and its succulent collection.

The San Francisco Botanical Garden at Strybing Arboretum lost a Himalayan spruce, an African cypress and a white-blossoming camellia in that same March 21 storm. A total of 14 specimens, including a Chilean soap bark tree and Tasmanian pepperberry, were killed during this winter’s storms.

A beloved old oak tree toppled in the meadow of Filoli, the impeccably landscaped Woodside estate owned by the National Trust for Historic Preservation.. The drought has caused oaks’ root systems to weaken, according to Jim Salyards, Filoli’s director of horticulture. And the oaks’ canopies are top heavy because this was a “mast year” for the species, producing huge acorn crop

At UC Berkeley’s garden, the first task is to remove the debris so experts can get access to the damaged plant beds. This week, the garden’s fragrant scent competed with the odor of ethanol fuel as workers with chainsaws carefully severed branches. A parade of volunteers carried away the detritus.

It’s impossible to accurately assess the toll so soon after the storm. Plants don’t die like people do. For instance, a standing tree could look fine but then fail later.

Or it could look dead, then bounce back. For instance, many ferns look tattered, but they’ll recover. The garden’s once-elegant bamboo forest is battered — but because bamboo is a grass, it will regenerate.

When the cuttings arrive for Malisch’s propagation care, they’re first treated with chemicals to fend off microorganisms or fungus. Then they’re dipped in a hormone to encourage rooting, inserted into special soil and placed on a “mist bench,” routinely bathed in gentle fog. Different plants require different techniques.