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| Blooming magnolias at the San Francisco Botanical Garden. Photo: Alison Hawkes |
There’s not a whole lot blooming in mid-January, when native
Californian plants shut down for the winter. But if you head over to the San
Francisco Botanical Garden, you’re in for a treat.
The magnolia trees begin to blossom, unveiling voluptuous
pink and white flowers that blanket the paths in fairyland fashion. Magnolias
are not native to Northern California, but it turns out that these immigrants
have been persuaded to believe they are in the midst of the Central American
cloud forest, or in a sheltered valley in the Himalayas where they call home.
“When these are in full bloom, this pathway is solid pink
petals,” said botanical garden curator Don Mahoney on a recent tour of the
magnolia collection.
From mid-January until the end of March, more than 100
magnolias of various varieties bloom in the garden, a collection of rare
varieties unrivaled outside of China. Magnolias are prolific in the Southeast,
where they were once heralded as a kind of mascot of the Confederacy. But
that’s just the native U.S. variety, Magnolia grandiflora. In the rest of the
world, the ancient flowering trees have become increasingly rare and endangered
as development encroaches on the last wild populations, which makes the conservation
work at the San Francisco Botanical Garden at Strybing Arboretum especially
critical.
The winter bloom is the best time of year to enjoy the
garden’s unique magnolia collection, which dates back to 1939. Among the
standouts is a 90-foot Magnolia campbellii ‘Strybing White’ cultivar (probably
the largest in the world and named after the garden itself), the critically
endangered Magnolia zenii with 3-inch white flowers that blush purple, the
Magnolia dawsoniana, whose 10-inch bloom looks like flags fluttering in the
wind, and the Magnolia denudata with its exquisite lily shaped blossoms with
pure white petals. |
Magnolia campbellii ‘Darjeeling’ is considered one
of the most spectacular blooms. Photo: David Kruse-Pickler. |
For the San Francisco Botanical Garden, the conservation
work happens at a very local scale, even as it has international intent. After
the blossoms fall, staff collect the seed and propagate it in the nursery and
then plant the seedlings back in the garden, or send them out to other
botanical gardens that are collaborating on magnolia conservation.
The goal is to provide a reserve so
that one day, the magnolia species can be returned to their native lands. San
Francisco turns out to be a suitable place for many of these species in exile.
“We try to specialize in stuff that
no other botanical garden is specializing in, mostly due to our climate that’s
so unusual,” said Mahoney. “Because we’re so cold in the summer and relatively
warm in the winter.”
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Don Mahoney is propagating
magnolia seed. Photo: Alison Hawkes. |
Magnolias native to high elevation
cloud forests in Central and South America seem to work well in San Francisco,
so Mahoney said he’s trying to focus efforts on growing those varieties.
Associate curator David Kruse-Pickler has traveled to Costa Rica, Indonesia and
Ecuador to scout out magnolia seeds, and other plants for the garden. Currently,
of the 84 different magnolias the botanical garden grows, 11 species are listed
as endangered.
Considering all the trouble we have
with invasive species, it might seem risky to unleash newcomers into the Bay
Area’s already fragile ecosystems. But Mahoney and Kruse-Pickler insist that
magnolias are unlikely to cause trouble. As tropical species, they need more
water than the climate here provides, so gardeners have to supplement.
“We have to sustain them. They would
never make it on their own,” said Kruse-Pickler.
The magnolia family, Magnoliaceae,
is considered one of the earliest flowering plant families and dates to 100
million years ago, before the time of bees. In the wild, the flowers are
pollinated by beetles. In the botanical garden, it’s probably honeybees that
accidentally do the pollination, and the squirrels chow down on most of the
seed. Hawks use the trees for perching.
Each tree has its own unique story
of how it came to be in the garden.
The ‘Strybing White’ cultivar came
from a batch of seed from India in 1934 that was supposed to turn into the pink
Magnolia campbellii. Instead, two decades later (magnolias are late
bloomers) it surprised everyone when it flowered white with little drooping
tepals(the name for petals in species without a differentiated outer flower),
apparently the result of a cross-pollination with another magnolia variety. The
cultivar became highly prized and was considered in Europe to be the classiest
of cultivated magnolias. That tree is still alive and well in the garden.
The Dianne Feinstein tree, a Magnolia
amoena, was one of the last of its kind in the wild, a gift to the
California senator from the Shanghai Botanical Garden.
“It’s a tiny, itty-bitty little flower, but it’s just exquisite,” said Mahoney. “It’s a very modest sized tree, but it can get covered by these little flowers that are brilliant, deep purple and white and they look like little bells hanging from the tree.”
Kruse-Pickler is headed to China in March during magnolia flowering season on a scouting expedition, paid for with private donations. Next year he’ll go back to collect the seed and bring them back to the garden.
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| Magnolias bloom above the Moon Garden at the San Francisco Botanical Garden. Photo: David Kruse-Pickler |
“I’m going first to see them, and actually see the wild origin,” he said. “So it’s going to be a very great trip. I’m really excited.”
With any luck, one day we’ll see them bloom.
Beginning January 12, the San Francisco Botanical Garden, Strybing Arboretum will have a series of docent-led tours and classes celebrating the magnolia bloom. Information is available here.
