Field Guide · Cryptomeria · Japan and the American South

The Cedar That Is Not a Cedar

Japanese cedar has been holding up shrine roofs, sake barrels and Southern property lines for a very long time, all under a common name that belongs to a different family entirely. A field guide to Cryptomeria japonica, the cultivars worth knowing, and the honest trouble the tree can give you in a humid summer.

11 min read · By Fiona von Grey · Aiken, South Carolina

IThe name that misleads

Start with the disappointment, because everything else is easier afterward. Cryptomeria japonica is not a cedar. True cedars sit in Cedrus, in the pines; this tree belongs to Cupressaceae, the cypress family, alongside the bald cypress in your local swamp and the junipers in the fencerow. For most of the twentieth century the botanical literature parked Cryptomeria in a family of their own, Taxodiaceae, with the redwoods and the taxodiums. That family has since been folded into Cupressaceae and quietly retired, which is why an older reference book and a new one will file the same tree in two different places without either being wrong at the time of printing.

The genus is monotypic as Kew treats the group: one accepted species, Cryptomeria japonica, and nothing else. The name comes from the Greek for hidden parts, a reference to the concealed floral structures, and japonica tells you where Europeans first met the tree rather than where the tree stops. Chinese populations exist, scattered through Fujian, Jiangxi, Sichuan, Yunnan and northwestern Zhejiang, and here the authorities part company. Flora of China and the Gymnosperm Database recognize them as var. sinensis, separated on leaf angle, cone scale count and seeds per scale. Kew's Plants of the World Online recognizes no infraspecific taxa at all. Recent genetic work using nuclear markers finds real differentiation between the Japanese and Chinese lineages, with divergence dated somewhere in the last few hundred thousand years, but stops well short of proposing a second species. If you see Cryptomeria fortunei on an old label, that name was never validly published; the plant is var. sinensis under a name that did not survive review.

A tree that has been in cultivation for a thousand years accumulates names the way a barn accumulates tools, and about as tidily.

IISugi, and the forest that outlives the argument

In Japan the tree is sugi, and sugi is not a garden plant so much as a piece of national infrastructure. Shrines and temples are enclosed by them. Sake has been aged and served in barrels coopered from the wood, which is light, straight-grained, aromatic and strongly rot resistant, and the Yoshino cedar of Nara has long been the barrel-maker's preferred timber. The avenue leading to Nikko is, by the Guinness reckoning, the longest tree-lined avenue in the world at 35.41 kilometers; the planting ran from 1628 to 1648, and of roughly 200,000 original trees something over 13,500 still stand, averaging 27 meters.

Then there is Yakushima, the island off the southern tip of Kyushu, inscribed on the UNESCO World Heritage list in 1993 for a primeval forest of trees the islanders call yakusugi. You will read, in a great deal of garden writing, that the largest of these, Jomon Sugi, is 7,200 years old. That figure is folklore and worth retiring. UNESCO's own text claims trees over 1,000 years, which is a defensible statement. A radiocarbon date published in 1985 returned roughly 3,000 years and has been treated skeptically ever since. The hard, countable evidence is better and no less astonishing: a Cryptomeria trunk sectioned at six meters showed 1,776 annual rings, and ring-counted ages of 1,345 and 1,400 years have been published for two Yakushima trees. Jomon Sugi is 5.2 meters through and 25.3 meters tall. That is enough. The tree does not need the extra four thousand years.

One more piece of the story, and a melancholy one. From the 1950s onward Japan planted sugi across the country to meet timber demand, and the species now covers roughly 4.5 million hectares, about 44 percent of all planted forest. Those stands matured, and every February and March they release pollen that travels more than a hundred kilometers. Kafunsho, Japanese cedar pollinosis, has climbed through successive national surveys from 16.2 percent of respondents in 1998 to 26.5 percent in 2008 to 38.8 percent in 2019. Those are self-reported figures and an earlier peer-reviewed survey, corrected for misdiagnosis, put the number nearer 13 percent, so take the headline with care. The direction of travel is not in dispute. A country planted a magnificent tree at enormous scale and gave itself a national allergy in the process, which is as good a parable about monoculture as forestry has produced.

IIIWhat the tree asks for in a Southern garden

Sugi came to the American South as a replacement for something that failed, which is not a romantic origin but is an honest one. Leyland cypress went into hedge rows across the Southeast for thirty years and then began dying in them, and Clemson now names Cryptomeria 'Yoshino' outright as an excellent replacement. That is the tree's commercial life here: a screen, a windbreak, a green wall along a property line. The tree is capable of a good deal more, and is worth siting as a specimen where there is room, because the bark is a fine cinnamon red and exfoliates in strips, and the branching tiers out with age into something architectural.

Cryptomeria japonica, the species
Family	Cupressaceae (formerly placed in Taxodiaceae)
Mature size	50 to 70 ft tall by 20 to 30 ft wide in US cultivation; to 150 ft in native forest. Dwarf cultivars 3 to 4 ft.
Hardiness	Sources give 5a to 9b (NC State), 5 to 9 (Clemson), 6 to 8 (Virginia Tech). Aiken at 8a sits comfortably inside all of them.
Growth rate	Reported as medium, slow to medium, and fast, depending on cultivar and site. Treat as moderate to fast.
Light	Full sun to dappled shade. In the southern part of the range, morning sun with afternoon shade is the better bet.
Soil	Rich, moist, acidic (pH below 6.0), well drained. Adaptable to clay, loam and sand.
Water	Not a drought plant. Irrigate through Southern dry spells, established or not.
Exposure	Wants air movement; does not want high wind.
Deer	Rutgers rates the tree "seldom severely damaged," the second of four categories. Clemson adds rabbit resistance.

Two of those lines carry more weight than the rest. The first is water. Sugi looks like a tough conifer and is not one, at least not in the way a juniper is tough. Missouri Botanical Garden says plainly that the soil should not be allowed to dry out; Clemson says the trees need irrigation during drought. In an Aiken August that is not a footnote, it is the whole difference between a green screen and a row of brown regrets.

The second is where you put the plant relative to the morning. Ed Gilman's work at the University of Florida contains the single most useful siting sentence in the literature for growers in our latitude: the trees perform best with afternoon shade in the southern part of their range, and morning sun helps keep the foliage dry, which theoretically reduces foliar disease. Put those two ideas together and the siting rule writes itself.

IVThe cultivars, one at a time

There are hundreds. Japanese and European nurseries have been selecting sugi for centuries, and the range runs from timber clones to witches' brooms the size of a footstool. These are the ones a Southern gardener is most likely to meet, with the reservations attached where the reservations are real.

'Yoshino'

The screening standard, and the reason most people in the Southeast own a Cryptomeria at all. Fast, narrowly pyramidal to columnar, blue-green, with a slight bronze cast in cold weather. Clemson gives 30 to 40 ft by 20 to 30 ft; NC State says 30 to 50 ft. Recommended by Clemson as the Leyland cypress replacement. Worth knowing that no extension source I could find rates 'Yoshino' as more or less blight-prone than the species, despite a good deal of confident opinion online in both directions.

'Radicans'

The one to plant for a client who will telephone you about winter color. More compact and more strictly columnar than 'Yoshino', 40 to 45 ft by 15 to 20 ft, and the needles hold dark green through winter with markedly less bronzing. The American Conifer Society also reports 'Radicans' as less prone to tip blight and leaf spot than others in the species, which is the only comparative disease claim in the group I could verify from a credible source. Originated in 1941 as a Japanese forestry selection; Takenoshin Nakai hoped to name a botanical variety for the plant and peer review declined.

'Black Dragon'

A dense, irregular, slightly gnarled small conifer, 8 to 10 ft by 4 to 6 ft, whose light green spring growth darkens through summer to a green so deep the plant reads black in shade. Winter deepens the color rather than bleaching the plant, so no bronzing. One honest caution comes with the drama: 'Black Dragon' carries heavy crops of male cones that hang on the plant, which Clemson calls undesirable and which recommends 'Gyokuryu' instead for anyone who will mind.

'Sekkan-sugi'

Vigorous, dense, upright, roughly 20 to 25 ft, and grown entirely for the new growth, which emerges a creamy yellow-white at the shoot tips. Set expectations honestly for a Southern client: that cream is a spring and early-summer color that our summer heat washes out to green. Oregon State also flags real nomenclatural confusion around this name, with some references treating 'Sekka Sugi' as a synonym of the quite different 'Cristata'. Buy the plant in growth, from someone who knows which one they have.

'Elegans', the plume cedar

The strangest of the common cultivars and the most interesting botanically. Cryptomeria normally passes from soft juvenile needles into stiff adult awls; 'Elegans' never makes the transition, holding feathery juvenile foliage 12 to 25 mm long for life. The plant is a permanent adolescent, and looks the part: soft, billowing, faintly unserious next to the species. In winter the foliage turns a rich brownish red to purple-brown, most intensely on exposed sites. Two cautions, both sourced: Oregon State reports the cultivar is subject to damage by wet snow, and Virginia Tech found 'Elegans' especially disease-prone in southwestern Virginia. 'Elegans Viridis' does not brown in winter; 'Elegans Aurea' goes yellow rather than red.

'Globosa Nana'

The dwarf, described and named in 1923 and thought to have reached the trade through Europe from Japan. A slow rounded bun, 2 to 4 ft tall by 3 to 4 ft wide, bluish-green in summer and rusty red in winter. NC State rates the plant resistant to deer, drought, dry soil, heat and salt, and records no significant problems, which makes this the toughest member of the group and a genuinely useful small evergreen. Zones 6a to 9b.

'Barabits Gold'

Selected by the Barabits nursery family of Sopron, Hungary, though I could not confirm that attribution from a primary source. The RHS describes a vigorous plant with semi-pendent branching, reaching around 5 m in ten years and 4 to 8 m at maturity, with new shoots pale gold in spring and summer and a bronze tint in late autumn and winter. Note the word vigorous. Anyone selling 'Barabits Gold' as a dwarf is selling you a surprise.

'Lemonade'

A rare cultivar in very limited circulation, with soft pale-yellow new growth that settles toward chartreuse. Honesty compels a caveat here: the documented institutional source for 'Lemonade' is a plant record in the JC Raulston Arboretum database, and there is no American Conifer Society or RHS entry, no extension factsheet, and no published mature size we could stand behind. We grow the plant, we like the plant, and we will tell you what we have observed on our own benches rather than repeat a specification that nobody has established. That is the difference between a rare plant and a well-documented one, and both are worth growing.

VWhy the needles go copper in January

Every winter, somewhere in the Southeast, a homeowner photographs a browning row of Japanese cedar and sends the picture to an extension agent. Most of the time nothing is wrong. NC State's Plant Disease and Insect Clinic lists normal cold-weather bronzing of Japanese cedar as a benign cause of whole-row browning that gets mistaken for disease, and the clinic says so because they see the samples.

The chemistry is worth knowing. As the plant cold-acclimates, chlorophyll declines and a red-brown xanthophyll called rhodoxanthin accumulates in the needles, where the pigment acts as a light screen. Winter sun on a cold leaf is dangerous; the photosynthetic machinery cannot use the light and the excess energy does damage. Rhodoxanthin is the tree's sunscreen. The pigment builds in sun-exposed needles and not in shaded ones, and non-bronzing mutants fail to make the pigment at all, which is precisely why the trait varies so sharply between cultivars. A 2025 common-garden study found the response conserved across every provenance tested.

A second and quite separate kind of browning is desiccation, not pigment. Virginia Tech notes that foliage tends to brown on the south side of a plant in winter through moisture loss, greening again in spring, and Gilman notes the same on windy sites in the northern half of the range. Both are cosmetic. Neither is a fungus.

The tree is not dying in February. The tree is wearing a coat.

VIThe honest cautions

The dieback nobody has named

Here is the part that most catalog copy omits. Virginia Tech reports that branch dieback on Cryptomeria in the southeastern United States, some of it leading to tree death, has been surfacing for several years, and that there are at present no definitive diagnoses. NC State's diagnostic clinic is blunter still: most cases of twig dieback on Japanese cedar, they write, have defied explanation. Passalora sequoiae, the Cercospora needle blight that devastates Leyland cypress, does list Cryptomeria among the host genera, and the symptom pattern is diagnostic when present, browning along the stem and on the lower branches first, then working upward and outward until only the branch tips stay green. But the region's own diagnostic labs decline to pin the Southeastern Cryptomeria decline on that organism. Anyone who tells you confidently what is killing Japanese cedars in the Southeast is ahead of the plant pathologists.

Pestalotiopsis, and stress

Pestalotiopsis funerea is a genuine Cryptomeria pathogen, and a secondary one: the fungus infects conifers already weakened by stressful growing conditions. Foliage yellows then browns from the tip, worst on the lower and older growth, with tiny black fruiting bodies visible under a hand lens. Fungicide is generally not recommended in landscape settings. Spacing, sunlight, air movement, no mechanical injury, and a plant kept vigorous are the whole treatment.

Size, and the thing about spraying

Fifty to eighty feet is a large tree for a suburban lot, and Gilman says so directly. Plant accordingly. Clemson adds the practical corollary that chemical control of disease and insects on large trees is out of reach for a homeowner because adequate coverage is impossible. Every meaningful lever on this tree is cultural: where you put the plant, how much room you give, when you irrigate, and whether the morning sun reaches the foliage. Choose well at planting and you will not need a sprayer at all.

VIIOn the cutting bench

Sugi roots, and roots willingly, which is why Japanese growers have propagated the tree clonally for more than five hundred years. The useful modern reference for our purposes is Jull, Warren and Blazich, working on 'Yoshino' and published in HortScience in 1994. They took cuttings at four growth stages and from four positions on the plant, treating with IBA from zero to 9,000 mg per liter. The best rooting, 87 percent, came from hardwood tips and semi-hardwood proximal halves of first-order laterals; softwood proximal halves of first-order laterals followed at 78 percent. The pattern is consistent and easy to carry to the bench: take from first-order laterals, and take material containing lignified wood rather than the soft tips of second-order shoots.

Japanese work adds one more lever worth knowing. Running a cool top and a warm base, roughly 10 degrees Celsius at the apex against 25 at the bottom, lifted rooting to 93 percent against 13 percent in untreated controls. Bottom heat under a cold frame is not a new idea. It is simply an idea this species rewards more than most. If you are taking cuttings this month, our notes on the summer craft of making more from less cover the rest of the setup.

Where sugi belongs in a Southern planting

As a screen, plant in a loose, staggered double row rather than a tight single line, and read our argument for planting a thicket instead of a wall before you order; a mixed screen with Cryptomeria in the structure survives what a monoculture does not. As a specimen, give the tree the room to tier and site the trunk where afternoon light will catch the cinnamon bark. And plant in the cooling, not in the heat, which is the whole argument of our fall planting guide for the Southeast. For the wider cultural story of the tree in Japan, our earlier piece on the journey from sakura to sugi sets sugi among the rest of Japan's botanical heritage.