Cryptomeria japonica is a magnificent evergreen that can live for centuries and grow two hundred feet tall. It is an ancient species, and dinosaurs once wandered beneath these trees. It is found only in Asia, North America, and, of all places, Tasmania!
It is the national tree of Japan, and in North America it is commonly called Japanese cedar, though it is not a cedar at all. It is actually a cypress and is in the Taxodiacceae family, which also includes the dawn redwood, California redwood, and bald cypress. Its needle like leaves are arranged in spirals, and it has reddish bark that peels off in long vertical strips. It produces one to two inch cones, and its pollen is famous for causing hay fever in its native Japan.
There are actually two varieties. Japonica has a dense habit and thick spreading branches. Sinensis has slender, drooping branches and a looser habit. Many of the ornamental cultivars are grown from sinensis. Cultivars of the tree are commonly much smaller than the species, usually growing less than sixty feet tall, with some being suitable for bonsai.
Cryptomeria japonica var. sinensis 'Radicans' grows in my garden. Three years ago I purchased it as a six foot specimen and used it indoors as a living Christmas tree for a few weeks before planting it out in my yard. Now it's at least twice that tall. Eventually it should grow to about forty feet tall by twelve to twenty feet wide.
Cryptomeria has soft blue green foliage that will turn bronze to purplish in cold winters. It will grow in zones 6-9 in full sun to partial shade and likes plenty of water, though it will do best in well drained soil. It will grow in sandy to clay soils with a ph of 5.5 to 7.5.
In Japan the species is commonly used in construction. The pinkish-red wood is waterproof and resistant to decay. Here in the United States, cultivars are usually grown as ornamentals. When I bought my tree, I was concentrating on how it would look with ornaments hanging all over it (beautiful), rather than its impact on the landscape. This time I was looking for something different, and I liked the look of Crytomeria's branches.
Now that it is growing in the garden, I am even more pleased with my choice. It is well suited to my zone 7b climate, and I think it will do well as it matures. Dinosaurs will never brush against its branches, but I have seen a few lizards!