General Sherman

General Sherman is a giant redwood (Sequoiadendron giganteum) in California’s Sequoia National Park. At 83.8m in height, 11m in diameter (31.3m circumference) and with an average crown spread is 32.5m, it’s the largest known living single-stem tree on Earth, visited by two million people annually.

Named after the American Civil War general, William Tecumseh Sherman, this world-famous tree is believed to be 2,300 to 2,700 years old. It was cited as the world’s largest tree in 1931 after a change in standards and a comparison to the nearby General Grant, another giant sequoia.

Perhaps not coincidentally, the world’s tallest tree is also in California. Hyperion, a 600-800-year-old coastal redwood (Sequoia sempervirens) in Redwood National Park has been measured at over 116m.

In 2006 General Sherman lost its largest branch which was a trunk-sized 30m long and 2m wide. The breakage isn’t thought to be related to poor health and may even be a defence mechanism.

This legendary specimen went on to survive a major fire in 2021 that killed roughly 2,000 giant sequoias. The forest fires of that time are thought to have killed 3-5% of the species’ population.

Giant redwood (or sequoia) is part of the Cupressaceae (cypress) family and Sequoioideae (sequoia) sub-family.  It’s native to western US, where it’s an endangered species (< 80,000) but has been extensively exported to mainly temperate zones. As a pioneer species it can thrive on barren land but it is susceptible to shade-tolerant species that prevent its seed germination.

The super-thick, fibrous, sequoia bark has evolved with its environment and resists fire well, reaching an unmatchable 90cm of thickness. In fact, this species needs periodic fire to clear competing vegetation and soil humus.

Sequoiadendron giganteum produces seed cones, with largest specimens able to disperse 300,000-400,000 winged seeds from 11,000 of them. These cones take 18-20 months to mature, turning from green to brown in the process, but can remain closed for up to 20 years – a mere bagatelle when you consider that sequoia can live for over 3,000 years.

Giant redwood leaves are small (3-6mm), arranged spirally and distinctly coniferous. They’re often described as awl-shaped in reference to a cobbler’s awl, a slender hand tool used for piercing leather that tapers to a sharp point.

Image (L) by Marty Aligata, own work, CC BY-SA 4.0; image (R) by Elizabeth Wu, National Park Service (USA)

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