How Many Species of Redwoods Live in California?

The world seems to need more redwoods. Few species serve to awaken our awe and admiration more immediately than these soaring giants, among the tallest and most massive beings extant. Three different species of redwoods are recognized, all with wood that is red in hue but very different in other aspects. Each type has its own genus, its own specific growth requirements and its own story. All three grow in California.

The coast redwood loves cool, coastal fog and grows slender and tall, its head in the clouds. Coast redwood (Sequoia sempervirens) at one time covered most of the West Coast of the United States, but today few are found outside of a narrow strip scattered along the northern California coast. In ideal conditions, a coast redwood will gain 30 inches a year for an entire century, growing to 350 feet high, but weather and soil can strongly impact growth rate. Coast redwoods thrive in U.S. Department of Agriculture plant hardiness zones 7 though 9, where a few specimens have lived more than 2,000 years.

It is the most massive living organism on earth -- the giant, or sierra, redwood (Sequoiadendron giganteum) and one of those with the greatest longevity. These magnificent trees are slightly shorter than the coast redwood but twice as hefty, with ground-level diameters of up to 35 feet. The General Sherman Tree, the largest giant sequoia, weighs some 12 million pounds, standing 273 feet tall with a 102-foot circumference at its base.The giant sequoia is found only in the wild in the western Sierra Nevada mountain range; however, transplants can grow in USDA zones 5 through 8. Many of these trees were seeded around Europe, where groves have thrived for more than a century.

The dawn redwood (Metasequoia glyptostroboides) has a long history, and fossil records place it on the earth over 50,000,000 years ago. It was considered extinct until 1941, when one was discovered growing in China. That one tree's seeds repopulated the globe, and today dawn redwoods are likely available at your garden store. The only deciduous redwood, the dawn redwood's bright-green needles turn maroon in autumn and fall. The tree grows to about 100 feet tall in U.S. Department of Agriculture plant hardiness zones 4 though 8.

No two of the redwood species share the same genus name, because significant differences distinguish each from each, but the story of their christenings is a convoluted one.

The first to be classified scientifically was the coast redwood, which was initially lumped into the bald cypress genus as Taxodium sempervirens, the species name indicating evergreen. However, when it was determined that this redwood was of an entirely new genus, it was renamed Sequoia sempervirens after a famous Cherokee scholar.

When another red-barked tree was located in the Sierra Nevadas, British scientists decided to call it Wellingtonia gigantea after the Duke of Wellington, while Americans called it Taxodium washingtonianum, after George Washington. Finally a French botanist linked the tree to the coast redwood and called it Sequoia gigantea. Later, the Latin word for tree, dendron, was added to its genus name to mark the differences between the trees.

The dawn redwood is closely related to and resembles the coast redwood, but it was initially identified as a water pine (Glyptostrobus pensilis), hardy in USDA zones 8 though 9. Eventually botanists recognized that it was a living member of a genus of trees that had previously been considered as containing only extinct trees: Metasequoia, meaning "close to Sequoia" according to Oregon State experts.