Cryptomeria is a monotypic, meaning there is only one species, genus of evergreen trees native to Japan and possibly China. C. japonica, known as the Japanese cedar or Sugi, is the single species in this genus. In Japan, it is widely cultivated in a variety of settings. Landscapers outside Japan sometimes select this tree for gardening needs. It can be highly suitable as a shade tree, privacy screen, or garden feature.
A mature Cryptomeria can grow up to 230 feet (70 meters) tall. These trees grow at a moderate pace, maintaining a tight, conical shape when they are young and eventually branching out into a broad, leafy tree. The scale-like leaves overlap and cover the twigs in entirety, and the tree is infamous in Japan for producing pollen known to be highly irritating for people with allergies.
These trees grow in United States Department of Agriculture (USDA) zones five through nine, preferring rich, well-drained soil, although they will grow in other soil conditions. They need to be trimmed while growing to keep the growth even and tidy and to open up the tree, limiting light blockage and keeping the tree healthy. Trees left unpruned can develop mold and mildew infestations and may become sick.
A number of cultivars of Cryptomeria have been developed. Dwarf cultivars designed for low maintenance gardening are available, along with trees developed for use in bonsai and in container gardening. Gardeners interested in cultivating Cryptomeria in containers will need to prune and wire the trees to achieve desired shapes. In the case of bonsai, classes are available for people who want to learn about the aesthetic and cultural traditions behind bonsai cultivation.
This tree is the National Tree of Japan. It is often seen in cultivation around shrines and other important sites, including in long avenues of stately trees, some of which are quite old. Mature trees are felled for their light, aesthetically pleasing timber, which can be used in construction and furniture making. Despite the name, the Japanese cedar is not actually related to true cedars, and lacks the distinctive scent associated with cedar trees.
Nurseries sometimes have Cryptomeria seedlings and they can also order them by request from customers. It is also possible to order trees directly from nurseries. This may provide access to unusual and interesting cultivars that are not in wide circulation. When planting a seedling, it is advisable to prepare the soil well and consider the placement carefully, as the tree can live for a very long time.