The redwood tree is part of the taxodium or Taxodiaceae family. The trees belong to the swamp-cypress family of cone-bearing trees or conifers and are not a fir tree. Based on fossil discoveries from Asia, North America and Europe, there were about 12 different species of redwood. Only three of these survived the ice age of 20 million years ago, namely the coast redwood, the dawn redwood (Metasequoia glyptostroboides) and the giant sequoia (Sequoiadendron giganteum).
The coast redwood tree is the tallest of the three redwoods with its mature height of 300 feet or more. The tree is also the longest lived, achieving an age of 2,000 years. The tallest living specimen of redwood is in California's Redwood National Forest. The tree, named Tall Tree, is 367.8 feet tall. The shallow roots grow 10 feet deep and encircle the tree in a diameter of up to 125 feet.
Young redwood trees have a narrow pyramidal shape with branches all the way down the trunk. On larger trees the branches do not start to grow until about one third of the length of trunk. The trunk has a heavily buttressed base with reddish brown, fissured bark. The ½-inch foliage on the tip and flowering shoots is scalelike, and that on the branches is 1-inch long, curved and linear. The tree produces egg-shaped, purplish cones that stay on the tree even after the seeds are released.
Redwood trees require a mild, humid climate for best growth and are intolerant of dry, warm weather. The fast-growing trees reach maturity in about 500 years and prefer a site that receives full to partial sun. Plant in a well-drained, moist soil and water trees regularly. Redwoods are hardy in USDA Zones 7 to 9 and are easily propagated with cuttings or seed.