Culture
Best grown in moist, rich, fertile, acidic, well-drained soils in full sun. Tolerates light shade. Soils should not be allowed to dry out. Site in a location protected from drying winter winds.
Noteworthy Characteristics
Cryptomeria japonica, commonly called Japanese cedar or sugi, is a slender, pyramidal, evergreen conifer with tiered horizontal branching, which is slightly pendulous at the tips. Japanese cedar is a monotypic genus unrelated to the true cedars (Cedrus). It is native to forested areas in Japan and China where it typically grows as a single trunk tree to 150’ tall (infrequently taller) with an 8’ trunk diameter. It is the national tree of Japan where it is often planted at temples and shrines. In cultivation in the U.S., it grows much smaller, more typically to 50-60’ tall. Sharply-pointed, awl-shaped, fragrant, green to blue-green needles (to 3/4” long) are spirally arranged. Foliage is soft to the touch. Foliage may bronze in cold winters. Spherical fruiting cones (to 1” diameter) appear at the shoot ends. Reddish-brown bark exfoliates in strips.
This is a prized timber tree in its native habitat.
Compact and dwarf cultivars are commonly sold in commerce.
Genus name comes from the Greek krypto meaning to hide and meris meaning a part in reference to the flower parts being hidden.
Specific epithet means of Japan.
'Spiralis' is a slow-growing semi-dwarf cultivar that typically grows to 6-8' tall over the first 10 years, but matures to as much as 30-40' tall over 50 years. Needles twist spirally around the branches in ringlets, hence the additional common name of granny's ringlets for this plant. Growth habit is variable. Plants generally form rounded mounds when young but become increasingly upright with age.
Problems
No serious insect or disease problems. Leaf blight and leaf spot.
Uses
Species trees as a large specimen tree. Screen. Dwarf cultivars make good rock garden plants.
Borders, foundations, rock gardens. Containers.