Sequoiadendron giganteum aka Giant Sequoia

Sequoiadendron giganteum, or giant sequoia, is an evergreen conifer. It belongs to the cypress family, Cupressaceae. Its native home lies in California's western Sierra Nevada. Some trees live for 2,000 to 3,000 years. Garden height varies with climate and growing conditions. North Carolina State gives 40–60 feet [12–18 metres] outside its native range. Oregon State gives a cultivated height of 100 feet [30 metres]. Reported widths span 25–60 feet [7.6–18.3 metres]. Wild trees can exceed 300 feet [91 metres].

Young trees grow fast and form a dense cone shape. Older trees lose low branches and spread their heavy limbs. These branches can slope down toward the ground. Thick, red-brown bark has deep grooves and a soft, fibrous feel. The blue-green leaves have sharp tips and overlap along shoots. Their shape ranges from small scales to narrow awls. Older stems shed their leaves, revealing red-brown, scaly bark. The leaves stay on the tree through winter.

This tree bears cones rather than true flowers or fruit. Male and female cones grow on the same tree. Cone buds form in late summer, with pollination in spring. Fertilization follows in summer, once cones approach their full size. Seeds ripen by the end of the second growing season. Oval, woody cones turn from green to red-brown. Some stay on the tree for up to 20 years. Heat, drying, and insect damage help release the winged seeds.

Giant sequoia needs ample space and a suitable climate. It grows best in cool conditions with steady soil moisture. Full sun suits it, though light shade is also suitable. Deep, fertile soil with good drainage supports growth. Sources differ on clay: RHS allows it, while North Carolina State warns against it. USDA guidance places it in zones 6–8; RHS rates it H6. It needs no routine pruning. Large gardens and parks can use it for shade and winter structure.

The tree shelters wildlife, and squirrels collect its cones. Chipmunks, sparrows, and finches eat the seeds. Mature bark helps protect trees from fire; young trees remain at risk. Pests seldom cause trouble, but problems increase outside the native range. Dieback, blight, and butt rot can occur. Honey fungus may also pose a risk. Its light, durable but brittle wood has construction uses. No edible or medicinal uses are known. PFAF reports no known hazards, rather than proven safety.