The world’s most massive singular tree in terms of volume, Sequoiadendrom giganteum hardly needs an introduction. Protected mostly on California forest preserves, these can grow over 91 meters tall with a canopy up to 18 meters across with a trunk up to 5 meters in diameter.
Sequoiadendron giganteum (Giant Sequoia, Sierra Redwood)
Hardiness Zones: 6-8
Height: frequently up to 76 meters (250 feet) tall, sometimes up to 100 meters (300 feet) tall, up to 27 meters (90 feet) tall in cultivation
Diameter: Trunks frequently reach 4.5 meters (15 feet) in diameter. The canopy spreads up to 18 meters (60 feet) across.
Growth Rate: faster than most other conifers, up to 0.50-0.75 meters (1.5-2.5 feet) annually in optimal conditions, slows noticeably past 400 years of age
Age: Healthy specimens live up to around 3,000 years old.
Root System: very extensive (up to 30 meters (100 feet) deep below the soil), grows very fast when yong (especially the first 2 years after germination), may cover up to 4 square acres, primarily taproot when young, lateral roots become prominent usually after 8 years old
Subspecies: ‘Pendula’ (grow to 3 meters (10 feet) tall, extremely dramatic drooping/wilting), ‘Haley Smith’ (blue foliage)
Tolerates: fires once mostly mature (necessary for survival in theirnative habitat), drought (not when young, very tolerant once mature), some very light shade
Problems (major): Few of these mature specimens (around 500) remain in the wild; they were overharvested to near extinction. Grows poorly in heavy, clay soils. Dry soils may kill off these plants. Temperature extreme highs and lows severely harm these and impede growth.
Problems (minor): Dieback, blight, and butt rot are all detrimental.
Poisonous: presumably no
Soil requirements: prefers deep, moist, well-drained loams
Air requirements: requires at least a fairly humid climate
Watering requirement: moderate, higher when younger, requires less with age
Sun requirement: full sun, can tolerate light shade for short periods of time
Needles: 0.5-1.0 centimeters (0.25-0.50 inches) long, scale-like, bluish-green
Cones (male): 2-3 centimeters (around 1 inch) long, tiny, egg-shaped, yellow, abundant in spring
Cones (female): 5-8 centimeters (2-3 inches) long, globular
Seeds require stratification: yes
Monoecious or Dioecious: monoecious
In terms of volume, Giant Sequoias are the largest living single-trunked organism (the Quaking Aspen (Populus tremuloides), Pando, has a larger volume including the root system and “clones”). These are the second tallest living organisms, second only to Coast Redwoods (Sequoia sempervorens). The reddish or cinnamon colored bark is extremely thick and very resilient to fires. These tend to be heavily buttressed at the base with nonresinous bark. The canopy is ovular to pyrimidal. Cones are typically pollinated in either April or May. A singular tree could possibly have up to 30,000 cones at any given time. An average of 1,500 cones are produced on a “typical” year, although one tree was thought to create up to 20,000 cones throughout one exceptional year. Seed germination andsurvival is anywhere from 20 to 40 percent. A 60 day stratification period for seeds from cones around 5 years old shouldproduce the highest rates of germination, potentially exceeding 50 percent. Phymatodes nitidus (a beetle, most effective animal for dispersal) and the Douglas Squirrel (Tamiasciuris douglasi) are major agents of seed dispersal. Fire also opens the cones, causing seed dispersl; this is likely the most important agent of dispersal (once the cones open, wind spreads the seeds to other areas). An estimated 400,000 seeds are spread out over 1 acre every year in native climates. Root cuttings and stump production are both fairly reliable methods of vegetative reproduction (at older ages, though, these become less successful). The General Grant tree reached a height of 94 meters (310 feet) tall.
These have been preserved in specialized forest preserves California and in some botanic gardens. These used to be logged nearly to extinction before Theodore Roosevelt began programs to conserve North America’s native flora and fauna. Do not attempt to havest any of the wood, foliage, cones, seeds,or anything from these; it is VERY illegal and immoral to do so.
The trunk of a Giant Sequoia
Multiple Giant Sequoias, foliage somewhat visible
An extremely buttresses trunk with a very deep fire scar
A large female Sugar Pine cone in relation to my grandfather standing next to an enormous Sequoiadendron giganteum trunk
A fairly large fire scar at the base of a large Giant Sequoia
Several moderately sized trees behind a fairly large building
A massive Sequoia in California at Sequoia National Park
These images were taken by a family member (my grandfather/grandmother); they were used here with permission. They may be used for educational and informational purposes only, provided that this article or online journal is appropriately cited or referenced first.