Cryptomeria japonica 'Radicans' / radicans Japanese cedar

Cryptomeria japonica 'Radicans' is a robust, fast-growing selection of Japanese cedar with columnar to pyramidal growth habit. It has dense, blue-green, feathery foliage that retains its color in winter with less bronzing than other Japanese cedars. After 10 years, ‘Radicans’ grows to heights of 30 to 40 feet (10-12 m) tall (sometimes up to 50 feet/15m) and 15 to 20 feet (5 - 6 m) wide. It is less prone to tip blight and leaf spot than other members of the species.

This cultivar originated in 1941 as a plant selected for the forestry industry in Japan. In 1941, Takenoshin Nakai (1882–1952) made a formal botanical study on the plant, hoping to be able to classify it as a specific variety of the species (Cryptomeria japonica var. radicans). Apparently peer revue determined that there was not enough distinction from the type to warrant such classification, rendering the results of the study synonymous with the typical species. "radicans" translates in "rooting" in the Latin language.

Cryptomeria japonica 'Radicans' — an attractive planting at a tree farm in South Carolina.
Photo by Fast Growing Tree, inc.

Comments

Maureen

How deer resistant is the tree, is it partial shade tolerant and what is the approximate rate of grow per year?

David Olszyk

Deer-resistance completely depends on the deer in your area. In my world (WA-state), deer never touch cryptos ... in the Northeast where there are more deer than food for them to eat, everything is fair game. Young plants are particularly susceptible to buck-rubbing, because the trees are straight and narrow when young.

This cultivar is tolerant of light shade, but might grow a little slower if not in full sun.

'Radicans' is selected in Japan for use in forestry. This implies really fast growth. I would not be surprised to see this one grow 2-3 feet per year.

Mike

This variety is always described as a maximum height of 30-40ft, maybe 50ft, but I'm wondering what its maximum eventual height might be many years later, for example in Japan (since even the variety was selected / developed there). Could it be this might be a 200ft tall tree in 500 years?

David Olszyk

30-50 feet is a 10-year estimate. If a plant is healthy and happy with its surroundings, there's no reason why it won't grow 3 to 5 feet a year for a century or two.

Malcolm

What about pruning? Can Cryptomeria japonica var radicans be pruned? Let's say, to make it more columnar and less pyramidal? If so, what's the best technique to use?

David Olszyk

no way ... grows too fast. You'll wear out yourself and your equipment. Best technique for you is to select a slower growing cultivar.