
Platycladus orientalis
Platycladus orientalis
Safety & Hazards
The essential oil in this plant contains thujone. Thujone is a GABA receptor antagonist which allows neurons to fire more easily. In larger doses this can cause muscle spasms and convulsions, and can also be toxic to brain, kidney, and liver cells. There has been a lot of negative press regarding thujone, particularly in the mid 19th century when thujone was reported to be more dangerous than alcohol - since shown to be exaggerated; and reports in the 1970’s that it might have a similar effect on the brain to THC (found in cannabis) – since found to be incorrect. Thujone is probably best known for its use in the alcoholic drink ‘Absinthe’. It is also found in the essential oils of many other plants that are used in herbal medicines and foods, including Arborvitae (Thuja species), some Junipers (Juniperus species), Wormwoods (especially Artemisia absinthium) and Sage (Salvia officinalis). There are some legal restrictions in various countries on the quantity of thujone that can be added to foods and drinks and these vary between countries. Side effects from consuming thujone can include sleeplessness and anxiety but, unless the pure essential oil is used, the quantity of thujone found in plants is well within safety levels. Pregnant women, however, may be advised to restrict their use of thujone-containing plants. The leaves are toxic if eaten[1]. The plant can also cause skin allergies in sensitive people[1].
Cultivation Details
Platycladus orientalis grows best in areas with a more continental climate of hot summers and cold winters. It often does not grow well in mild and moist maritime climates. In Britain, the best specimens are to be found in towns or cities away from the west of the country, such as Oxford, and in very sharply drained soils in gardens[2]. Prefers a moist loamy soil[3]. Grows best on dry freely draining sites, often alkaline in reaction[4]. Does well over old building rubble[4]. Tolerant of dry dusty sites and of atmospheric pollution in towns[5]. Prefers a sunny sheltered position[1]. The plant appears to be tolerant of drought, as well as the air pollution that occurs within the urban environment[6]. A substantial number of cultivars has been raised in Europe since its introduction to France around 1700, many of which are now obsolete, while new cultivars continue to be selected and described[6]. Easily transplanted[3]. There are many named varieties selected for their ornamental value. Produces seed freely in cultivation[4]. A slow growing tree[7, 4]. Plants cannot regenerate from old wood. Pruning is not normally necessary for this species, any pruning that is carried out should be done with care[1]. Plants are susceptible to attacks by honey fungus[1]. Plants are monoecious, male catkins being produced at the tips of branches and female cones at the base[8]. This tree is a favourite with Taoists, Buddhist and Confucian priests, which accounts for its wide spread cultivation. The fresh boughs are sold to worshippers at shrines and temples. Where Platycladus orientalis is abundant, monasteries and temples are never far away[6].
Propagation
Seed - best sown when ripe in the autumn in a cold frame. Stored seed germinates best if given a short cold stratification. It can then be sown in a cold frame in late winter. Plants make very little growth in their first year[9]. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. If there is sufficient seed it is worthwhile trying a sowing in an outdoor seed bed in mid spring[9]. Grow the plants on for at least two years before planting them out in the winter. Cuttings of half-ripe wood, 5 - 8cm with a heel, mid summer in a shaded frame. Forms roots by the end of September but should be overwintered in a frame[9]. Cuttings of almost ripe wood, 5 - 10cm with a heel, September in a cold frame. Forms roots in the following summer. Plant out in autumn or spring[9]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Platycladus+orientalis>
Pollinators
Wind
References
- [1]Encyclopaedia of Herbs and their Uses. — Bown. D. · Dorling Kindersley, London. · 1995 · ISBN 0-7513-020-31 ↩︎A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
- [2]Conifers in the British Isles. — Mitchell. A. F. · HMSO · 1975 · ISBN 0-11-710012-9 ↩︎A bit out of date (first published in 1972), but an excellent guide to how well the various species of conifers grow in Britain giving locations of trees.
- [3]Trees of Central Texas. — Vines. R. A. · University of Texas Press · 1987 · ISBN 0-292-78958-3 ↩︎A good concise guide, it gives details of habitats and some of the uses of trees growing in Texas.
- [4]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [5]Conifers. — Rushforth. K. · Christopher Helm · 1987 · ISBN 0-7470-2801-X ↩︎Deals with conifers that can be grown outdoors in Britain. Good notes on cultivation and a few bits about plant uses.
- [6]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
- [7]Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. — Bean. W. · Murray · 1981 · ISBN - ↩︎A classic with a wealth of information on the plants, but poor on pictures.
- [8]Medicinal Plants in Vietnam — Nguyen Van Dan & Doan Thi Nhu · World Health Organisation · 1989 · ISBN 92 9061 101 4 ↩︎An excellent book, giving information on over 200 plants, their medicinal compounds and applications.
- [9]Propagation of Trees, Shrubs and Conifers. — Sheat. W. G. · MacMillan and Co · 1948 · ISBN - ↩︎A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
- [10]Flora of China — Missouri Botanical Garden Press; St. Louis. · 1994 · http://flora.huh.harvard.edu/china/ ↩︎An excellent, comprehensive resource in 25 volumes. In addition to the botanical information the flora also gives basic information on habitat and some uses. An on-line version is also available.
- [11]Tanaka's Cyclopedia of Edible Plants of the World. — Tanaka. T. & Nakao S. · Keigaku Publishing; Tokyo · 1976 · ISBN - ↩︎The most comprehensive list of edible plants I've come across. Only the briefest entry for each species, though, and some of the entries are more than a little dubious. Not for the casual reader.
- [12]Famine Foods listed in the Chiu-Huang Pen-ts'ao. — Reid. B. E. · Southern Materials Centre; Taipei · 1977 · ISBN - ↩︎A translation of an ancient Chinese book on edible wild foods. Fascinating.
- [13]Medicinal Plants of China — Duke. J. A. and Ayensu. E. S. · Reference Publications, Inc. · 1985 · ISBN 0-917256-20-4 ↩︎Details of over 1,200 medicinal plants of China and brief details of their uses. Often includes an analysis, or at least a list of constituents. Heavy going if you are not into the subject.
- [14]A Barefoot Doctors Manual. — ? · Running Press; Philadelphica. · 1977 · ISBN 0-914294-92-X ↩︎A very readable herbal from China, combining some modern methods with traditional chinese methods.
- [15]Handbook of Chinese Herbs and Formulas. — Yeung. Him-Che. · Institute of Chinese Medicine, Los Angeles · 1985 · ISBN - ↩︎An excellent Chinese herbal giving information on over 500 species. Rather technical and probably best suited to the more accomplished user of herbs.
- [16]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
- [17]A Manual of Indian Timbers. — Gamble. J. S. · Bishen Singh Mahendra Pal Singh · 1972 · ISBN - ↩︎First written in the 19th century, but still a classic, giving a lot of information on the uses and habitats of Indian trees. Not for the casual reader.
- [18]Trees of North Texas — Vines. R.A. · University of Texas Press. · 1982 · ISBN 0292780206 ↩︎A readable guide to the area, it contains descriptions of the plants and their habitats with quite a bit of information on plant uses.
- [PFAF]Plants for a Future — pfaf.org ↩︎