The California redwoods, or sequoia, attract tree lovers and outdoor enthusiasts from around the world. The large and ancient trees are native to only the coastal areas of California and southern Oregon. The redwood forests of the California State Parks and U.S. National Parks are designated together as a World Heritage Site and International Biosphere Reserve.
The area along the northern coast of California and southern coast of Oregon is a unique habitat. Winters are mild with some snow and heavy rainfall. Summers are dry, but the cool breezes coming off the Pacific Ocean bring a fog that keeps the redwood forests moist all year. Dense stands of old-growth forest absorb moisture directly from the air and keep the forest environment moist, which helps other plants. The soil is supported by various species of fungus that aid in the decomposition of plant matter to help support the nutritional requirements of the trees.
The coast redwood (scientific name Sequoia sempervirens) is the tallest tree species in the world. The tallest tree, named "Tall Tree," in Orick, California, was measured at 367.8 feet before the top broke off in the mid-1990s. It was the same height as a 35-story skyscraper. Trunk diameters can reach up to 22 feet. Coast redwood trees are long lived and can reach ages of 2,000 years or more. They grow very rapidly to 100 feet, often 4 or 5 feet a year, then slow down as they age.
Giant redwood (scientific name Sequoiadendron giganteum) are slightly shorter than coast redwoods, obtaining a height of 300 feet or less, but they have a larger volume. Trunks can have a diameter of up to 41 feet. The largest living thing on the planet is a giant redwood named "Sherman" in Sequoia National Park in California---it weighs an estimated 2.7 million pounds. Giant redwoods live longer than coastal redwoods, reaching ages of up to 3,200 years.
Associated Forest Plants
Redwood forests support many different types of plants other than redwoods. A healthy stand also contains douglas fir and sitka spruce as the upper story of the canopy. Low canopy trees include big-leaf maple and California bay. Understory shrubs include wild rhododendron, sword ferns, redwood sorrel, and huckleberry. Many different species of lichens and mosses grow on the trunks of the giant trees.
Redwoods in Cultivation
Both giant and coastal redwoods can be grown in areas that stay mild year round. Giant redwoods can survive in USDA zones 6 through 8 and coastal redwoods in zones 7 through 10A. They like full sun and rich soil that is slightly acidic to slightly alkaline. The soil should remain moist for coastal redwoods; giant redwoods are slightly more drought tolerant.