Magnolias in bloom

They are the botanical equivalent of a Southern belle. With their voluptuous blooms in garden party colors, magnolia trees are as iconic to the Deep South as mint juleps.

But while about 10 percent of the world's magnolias do hail from the Southern U.S., they really don't like the tropics. Some 80 percent of magnolias are native to China and India, and thrive in more temperate climates.

They grow well in the North Bay and the greater Bay Area; in fact, conditions are so hospitable that foggy San Francisco is home to the most important collection of magnolias outside of China, and the fourth most important conservation collection in the world. Who knew?

Of the 70 different varieties and 160 individual specimens of magnolia gracing the 55-acre San Francisco Botanical Garden in Golden Gate Park, nine are included on the "Red List" of the International Union for Conservation of Nature, a global environmental organization with 11,000 experts who help set the standards for identifying the risk faced by both plant and animal species.

Among those is the small, deciduous and critically endangered Magnolia zenii. Listed as "critically endangered," there were only a few left dozen of these found when the variety was first discovered in China in 1931.

This extraordinary collection is beginning to burst into flower now, visual relief in winter when precious little is in bloom. Some 100 specimens will put on a show before dropping their blossoms in a lush carpet of color that is almost as beautiful on the ground as on the branch, said chief curator Don Mahoney.

The garden is celebrating its impressive collection from now through March, with several special events, including monthly guided walks through the magnolias "by moonlight," and classes in pencil-drawing magnolias and mixing magnolias into tasty cocktails using two of the garden's famed varieties of magnolia. There are also kids' activities like mobile-making and a scavenger hunt, all tied to what has become the "signature flower" of the San Francisco Botanical Garden.

But more serious horticulturists and backyard gardeners will be content with a self-guided or docent-led tour of the magnolia collection, to view some of the garden's most significant trees as well as browse among others more commonly found. If you're dreaming of planting one, the best time to shop is when they are in bloom.

It's a a trek that will take you off the main paths to manicured spots like the Japanese Moon-Viewing Garden, with a pool that reflects the full moon and lush corners that are almost primeval in appearance. Paleobotanists regard the magnolia family as one of the oldest flowering plants, with fossils dating back nearly 100 million years.

All told, they consume several acres of the garden, and are most likely to be found, said Mahoney, with classic companion plants like camellias, rhododendrons and ferns.

What makes a blooming magnolia so magnificent, he stressed, is the fact that the flowers bloom on naked branches; no greenery dilutes the sight.

"A big old one can have 4-5,000 flowers and it's just incredibly colorful," said Mahoney. He will lead a public tour on Feb. 16, pointing out important highlights, like the red-listed Magnolia amoena, which Sen. Dianne Feinstein brought back from an official visit to Shanghai in 1984.

"It's white with dark purple bands in it," said the curator, who oversees some 8,000 different plants from around the world. "It's very exquisite, a piece of art."

The magnolia obsession started with Eric Walther, a protege of Golden Gate Park founder and 50-year superintendent John McLaren. Walther procured seed of the species campbellii from Darjeeling, India and planted it in the park, later moving it to the new arboretum. In 1940, not long after the park opened, a campbellii bloomed, the first ever to flower in the U.S., with massively majestic flowers, perhaps the largest of any magnolia. (Magnolias are trees that demands patience. It can take a seedling 20 years to bloom.)

The horticultural event drew throngs to the new arboretum, lining up to view the tree blooming behind a wooden fence.

Park visitors can still see that tree, which last year produced flowers measuring 13 inches across, as well as other venerable survivors, like the Magnolia campbellii 'Strybing White,' at 80 feet the largest in the park and producing an unexpected white bloom.

You can reach Staff Writer Meg McConahey at meg.mcconahey@pressdemocrat.com or 521-5204.