Sequoiadendron giganteum, known as giant sequoia, has the most massive size of any tree in the world. It is an erect, single-trunk (often buttressed at the base), needled evergreen conifer that is native to groves scattered through montane coniferous forests along the western slope of the Sierra Nevada Mountains (4500-8000 feet in elevation) in central California. In its native California habitat, mature trees will often grow to 200-275’ tall, produce trunk diameters ranging from 15-20’ and weigh 200 or more tons. Trees may live 2000-3000 years. Young trees have a pyramidal-oval shape. As trees mature, they begin to lose branches from the lower part of the trunk. Trees generally feature attractive dark cinnamon-brown bark (with deep furrows and ridges), small, scale-like, appressed, blue green needles and fruiting cones to 2.5” long. Trees may be planted in the eastern U.S., but typically will grow to only 40-60’ tall. Giant sequoia was originally discovered in 1833 by Zenas Leonard. A very large percentage of giant sequoias in California are now protected in parks, including Yosemite, Sequoia and Kings Canyon National Parks. Sequoiadendron giganteum and its close relative, Sequoia sempervirens (redwood), are jointly designated as the State Tree of California. Other common names are big tree and giant redwood. Best grown in moist, deep, loose, well-drained, sandy loams in full sun. Tolerates some light shade. Grows best in cool, moist climates with consistently high moisture levels. In its natural habitat, this is a very large tree that needs a very large space. In the right climate, young trees make attractive additions to large gardens.
The seeds have a period of dormancy. They can be planted outdoors in the fall or winter for spring germination or they can be cold stratified to simulate winter conditions and to break their dormancy at any time of the year.
- Place the seeds in a plastic bag and seal it. Store the bag in a refrigerator for 10 weeks.
- The seeds like moist, well-drained soil. Fill a pot with a mixture of equal parts potting soil, sand and compost. Water the mixture so that it is moist but not wet.
- Sow the seeds on the soil and cover them with a thin layer of soil.
- Water the container and leave it to drain.
- Put the pot in an area that is in light shade.
- Water the pot regularly so that the soil is moist but not wet.
- The seedlings can be transplanted when they are a few inches tall.