These three popular regional varieties of Juniperus chinensis are discussed often, but rarely are their features compared. A few good articles exist that describe them, including Brent’s site, as well as this archived history of the shimpaku (although neither site shows a photo of Kishu). Here are some observations and comparisons of each. As always, please feel free to share your experiences as well!
First, it’s easiest to begin by looking at all three varieties. From left to right: Itoigawa, Kishu, and Shimpaku.
The Itoigawa and Shimpaku came from Brent Walston, and the Kishu came from Miniature Plant Kingdom, via Plant City Bonsai, so their provenance is documented and trusted.
First, the Itoigawa. This variety was discovered later than Shimpaku, and was responsible for the appearance of the dramatic, carved deadwood look on collected junipers. Itoigawa was named for the city where they were discovered; at modern-day Niigata, which is on the west coast, nearly due West of Fukushima. The bark of Itoigawa has less of a red hue than Shimpaku. The foliage is very bright sea-green in color. It is naturally less compact by comparison, reverts to juvenile foliage after heavy pruning, which is slightly bluer, but still soft. The mature scales are the smallest of the three and can become dense with regular pinching. Shoots are finest in texture of the three, yet it grows faster than shimpaku.
Kishu was also named for the city nearest their discovery. Kishu is at the Southwest corner of the mainland. Kishu is also bright green, similar to the Itoigawa, but the foliage is very dense, compact, and “stout”. Comparing Shimpaku to Kishu is like comparing the species Japanese Black Pine to a Yatsabusa black pine. Kishu is often used for grafting to replace other juniper foliage because it does have desirable traits; dense, thick growth and bright green color. Foliage seems to grow in thick tufts along the branches. Bark is reddish in color, similar to Shimpaku.
The Shimpaku was discovered on the Ishizuchi mountain range on the Northern part of Shikoku island, which is south of the mainland. Shimpaku was originally collected from the mountains and enjoyed as bonsai with little to no training or styling. Slender trunks were appreciated. “In “Bonsai Gahou (Magazine)” No. 5 (September 1907 issue), there is a discussion of the origin of Shimpaku bonsai. It says that in 1889 a bonsai lover, Rokurou Ohta, obtained a juniper bonsai that reminded its admirers of a famous painting of “Kanzankokai” (an old Japanese cypress in the winter mountain). The rumor spread among the traders that “this is the authentic (=shin), oak (=paku).” Thus, the juniper was named “Shinpaku.” (Accounting for the conventions of Japanese word combination, it becomes “Shimpaku.”) This word was not known in either the Chinese or Japanese language and so the name “Shimpaku” was conceived within the world of bonsai as a new variety of junipers.” 1.
Shimpaku foliage is rope-like in texture, blue-green in color, and very soft. Even the juvenile foliage is soft. Shimpaku will “revert” to juvenile foliage around areas of heavy pruning. Bark on Shimpaku is a reddish brown color, and the foliage becomes fairly dense in time.
Here is a photo of all three shoots together for comparison; still from left to right: Itoigawa, Kishu, and Shimpaku.
Hopefully this adds some clarity to the three varieties…or at least doesn’t add any contradictory information!