Chamaecyparis obtusa (Hinoki Cypress) bonsai tree is revered and highly prized for its elegance, dense growth and tight foliage. This charismatic tree is native to central and southern Japan. Since the plant does not belong to the Cupressus genus, it is sometimes referred to as a ‘false cypress’ or Japanese Cypress. In nature, this evergreen tree can grow up to 45 meters tall. When cultivated in gardens and parks, the tree stops growing at about 15 meters.
The dwarf forms are mostly used in bonsai art. Among them, the most popular are Chirimen, Yatsubusa and Sekka. There are hundreds of dwarf cultivars of Hinoki Cypress, but not all are suitable for bonsai. Most preferred are those which have compact foliage.
In Japan, the Hinoki Cypress is an important timber tree, used in art and construction. An ancient Japanese book described the Hinoki Cypress as ‘a good tree for building palaces’. It is said that some temple structures built from the wood of a Hinoki Cypress have lasted 1000 years. In both Shinto and Buddhism, Hinoki Cypress wood is considered sacred and pure. It is used as a building material for funeral equipment.
The tree is also valued for its fragrant essential oils. A less popular characteristic of the Hinoki Cypresses is that they cause spring ‘hay fever’ allergies. Due to overuse, the wild Hinoki Cypress is now classified as an endangered species.
The leaves are dark green, scale-like, blunt-tipped, with white stomatal lines underneath. They form layered fan-shaped shoots and fern-like branches. The branches droop at their tip. In winter, the foliage of Hinoki Cypresses turns brown-red. The foliage of the Golden Hinoki variety has an attractive golden tint. The trunk has peculiar, rust-colored bark, that peels in long strips. These characteristics of the bark makes even young specimens look elegant and mature. With age, the bark becomes more attractive.
The Hinoki Cypress is a monoecious plant, meaning that same tree holds pollen cones and seed cones separately. The cones are small (the size of a pea, or approximately 8-12 mm in diameter), solitary globular and contain 8-12 small winged seeds arranged in opposite pairs.
According to one interpretation, the word Hinoki is derived from hi (fire) and ki (tree). Hinoki Cypresses are sacred ‘fire trees’ of the polytheistic Shinto religion. Monks at Shinto shrines have traditionally used Hinoki Cypress wood to make fire by friction. Hinoki Cypress is used in many ceremonies and rituals. According to another etymological theory, the name Hinoki comes from the Japanese phrase ‘hi no ki’ which means ‘tree of the sun’. The epithet obtusa is a reference to the blunt leaves.
Several old Hinoki Cypress specimen can be found in bonsai collections in the West. Namely, on their way back from the East, many European and American merchants, travelers and statesmen often brought home interesting plant saplings. In the USA, there is an old collection of Chamaecyparis obtusa (Hinoki Cypress) trees. They were brought to the USA in 1913 by Larz Anderson, a former American ambassador to Japan. Some Hinoki Cypresses bonsai trees in this collection are over a hundred of years old. The most impressive specimen,’Chabo-hiba,’ is nearly 300 years old.
This guide provides the foundations of Chamaecyparis obtusa (Hinoki Cypress) bonsai tree care guide.
How Long Does It Take To Grow Chamaecyparis obtusa (Hinoki Cypress) Bonsai?
Chamaecyparis obtusa (Hinoki Cypress) has a lifespan of over 100 years. The rate of growth is medium, approximately 30 cm per year. Growing this bonsai tree requires not only patience, but also meticulous work and persistence. For this reason, novice bonsai enthusiasts are advised to assess their commitment before they undertake responsibility for this tree.
How to Plant and Grow Chamaecyparis obtusa (Hinoki Cypress) Bonsai?
Hinoki Cypress is an outdoor bonsai tree. It should not be treated as a houseplant. Although it is a very hardy and adaptable tree, it needs proper care. If neglected, can quickly deteriorate and die.
Chamaecyparis obtusa (Hinoki Cypress) is a conifer tree that produces roots from softwood cuttings (in late summer/early autumn). Alternative methods are air-layering and seed propagation. Propagation from seed is very slow, since the seeds need to be cold-treated before sown, and they may take up to a year to germinate.
Position, Lighting and Temperature Requirements
Chamaecyparis obtusa (Hinoki Cypress) is a hardy plant. However, if the temperature in winter falls below – 5°C, the plant needs protection. Dry, cold winds can be particularly harming to Hinoki Cypresses. In such conditions, the tree should be sheltered in a frost-free environment (for example, in a garage). Even then, the tree will need much light, and should be kept away from modern heating systems, to avoid loss of humidity. On the other hand, during the growing season, the plant can be exposed to full sun without any problem.
Soil and Watering Needs
Hinoki Cypresses prefer lime-free, slightly acidic and fast-draining soil.
From spring to late summer/early autumn, Hinoki Cypresses need regular watering. Although this is tree tends to absorb a lot of water, the roots should not be kept wet all the time, because excess watering can cause root rot. The water should be lime-free.
Misting is allowed, but needs to be done carefully, as the needles can sometimes get scorched due to the reflection of the sun rays over the water droplets. On the other hand, hot dry winds can also damage the foliage, so the tree needs sufficient humidity.
In winter, the compost needs to remain moist, especially during longer dry periods.
In early spring, one dose of high-nitrogen fertilizer should be used. In summer, two more doses of common fertilizer can be applied.
Alternatively, during the growing season, organic fertilizer can be used every month, and liquid fertilizer once a week.
Some experts recommend the use of pellet-based, slow-release fertilizer, which can be added to the soil every couple of months.
How to Care for Your Chamaecyparis obtusa (Hinoki Cypress) Bonsai?
Chamaecyparis obtusa (Hinoki Cypress) is not a low-maintenance bonsai species. It requires constant dedication and vigilant work. However, the Hinoki Cypress is also a very rewarding bonsai tree. As it ages, it becomes evermore stunning and valuable.
A scientific study has found that owning a Hinoki Cypress can have a very calming effect. According to the researchers, touching Hinoki wood calms prefrontal cortex activity and increases parasympathetic nervous activity. This, in turn, induces physiological relaxation. Hinoki essential oils have antibacterial and stress-relieving effect.
Most importantly, the Hinoki Cypress bonsai tree demands regular foliage maintenance. If pruning is neglected, most of the branches in the interior and lower part of the tree will die due to insufficient access to sunlight.
Hinoki Cypresses are often compared to Juniperus chinensis var. sargentii (Chinese junipers). Therefore, bonsai artists are advised to treat these two bonsai trees in a similar manner.
Pruning, Pinching and Wiring
From early spring to late summer, secondary branches can be pruned back. Pinching out of new shoot tips can be done multiple times throughout the growing season. Regular and continuous foliage trimming is necessary, else the inner leaves get less sunlight and die. The tree stops budding on old wood.
Pinching is better than pruning with scissors, since the foliage tends to turn brown in the spots where it has been cut. A good practice is to allow shoots to grow 2.5 cm before finger-pinching them. Also, messy and irregular pruning can result in formation of not-so-pretty whorls in the foliage. In summer, hard pruning should be avoided, since the exposed the inner foliage can die back.
The best time for wiring is spring or mid-summer. The process can be challenging, as no foliage should remain trapped under the wire, and the branches need longer time to set. In spite of that, the wire should not stay on the bonsai tree longer than ten months. If necessary, rewiring can be performed. To protect the tree from marks and scars, before any wiring is set, it is recommended to wrap the branches with raffia.
For younger Hinoki Cypresses, repotting should be done every alternate year, during late spring. Since the roots grow fast, more of the root mass can be pruned at the time of repotting. As much as a third (in exceptional cases a half) of the total root mass can be removed. Akadama soil is considered a suitable growing medium. Alternatively, a mix of loam, peat and sharp send in the ratio 1:1:1 can be used. The repotting of Older Hinoki Cypresses can be done less frequently, once in 4 – 5 years.
Pests and Diseases
Hinoki Cypresses are mostly vulnerable to scale insects bagworms and spider mites. If early detected, the insects can be scraped off from the trunk using a knife. Any advanced infestation should be treated with systemic insecticide. Tip blight is another common problem, which has to be treated with special fungicide. In autumn, the trees lose much of their old foliage. This is quite normal and should not cause any trouble. To improve the look of the bonsai tree, the brown foliage can be simply removed by hand.