Cryptomeria fortunei Seeds | Chinese Cedar
LATIN NAME: Cryptomeria fortunei
COMMON NAME: Chinese Cedar
Plant Profile
Chinese cedar is the southern form of the Japanese cedar, and it differs in ways that matter in a hot, humid climate: longer, softer needles, larger cones and a much greater tolerance of summer heat. The tree is a tall, narrow column when young, forty metres at maturity in good forest, with a straight trunk and a crown that broadens only in old age. The bark is reddish brown and peels in long vertical strips, and the foliage is arranged in dense, spiralling sprays of awl-shaped leaves, blue-green and soft to the touch, two centimetres long on the strong shoots.
The cones are round, about two centimetres across, green ripening to brown, with thick, peltate scales that separate to release small winged seed. The species is native to the hills of southern China, from Zhejiang and Fujian across to Sichuan, Guizhou and Yunnan, generally between six hundred and fifteen hundred metres, in moist mixed forest on acid soils. It has been planted for centuries around temples, villages and graves, and many of the finest old specimens are cultivated rather than wild. Botanists have argued for a long time about its status. Most modern treatments place it as a variety of Cryptomeria japonica, the only other member of the genus, while Chinese forestry continues to treat it as a distinct species on the strength of its longer leaves, larger cones and different growth rhythm.
Science & Biotechnology
The genus is monotypic apart from this taxon, which makes it unusually useful for studying how a single species adapts across a wide range. Comparisons of the Chinese and Japanese forms have looked at leaf anatomy, stomatal density, cold hardiness and the timing of shoot extension, and the differences are consistent with adaptation to a warmer, wetter, more southern climate with a longer growing season. The wood chemistry has also been examined: the heartwood contains diterpenes and sesquiterpenes, including cryptomerione, that give the timber its characteristic scent and its resistance to decay, and these compounds have been studied for insecticidal and antifungal activity.
The pollen is a public health matter in Japan, where plantations of the Japanese form cover vast areas and the spring pollen load is a national problem. The Chinese form sheds pollen a little earlier and in a slightly different pattern, and it is included in aerobiological monitoring where it is planted. Forestry research in China has treated the species as a plantation tree, with work on provenance trials, clonal selection, spacing, thinning and the genetics of growth and stem form. The species is also used in dendrochronology and in studies of forest carbon, since old individuals can live for many centuries and the wood preserves well.
Uses & Benefits
The timber is the main product. It is light, straight-grained, fragrant, easy to work and remarkably durable in damp conditions, which is why it has been used for boats, bridges, water tanks, barrels, furniture and building frames. In Japan the related form is the standard material for cedar-clad houses and for the sake of the scent alone. In China the tree is more often grown for shelter, for temple grounds and for the landscape, where its narrow juvenile habit makes it useful as a screen or an avenue tree.
As an ornamental it is a strong vertical accent, and it can be kept small by pruning or grown in a large container for years. It responds well to clipping and is used for formal hedges and for niwaki-style training. It prefers deep, moist, well-drained acid soil and a site with shelter from drying wind, and it grows faster than most conifers of the same size. The one drawback is its size: a tree that reaches forty metres needs to be sited with that in mind, not planted at the corner of a small garden.
Growing from Seed
The seed is small and should be sown on the surface of a fine, lime-free mix, pressed in but not covered, and kept at around twenty degrees in bright light. Germination begins in three to four weeks and is usually good. Keep the tray humid but airy, since the seedlings damp off easily in still conditions. Once they are two centimetres high, prick them out into individual pots of ericaceous compost and grow them on in a cool frame.
Plant out in autumn or early spring, when the seedlings are fifteen to twenty centimetres tall, into deep, moist, acid soil with shelter from wind. Water through the first three summers, and mulch with leaf mould or pine needles to keep the surface cool and acid. The tree grows quickly once established, up to a metre a year in good conditions, and needs no pruning unless a hedge or a clear stem is wanted. It is hardy to about minus twenty degrees, but late frost on new growth can brown the tips.
Our Take
A fast, handsome conifer for a large garden or a wet, acid site, and a useful timber tree where there is room. Give it space and acid soil, and it will outgrow almost everything around it.
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