Species of the week: Cymbidium goeringii 'Tian Cao' (天草)

A grassy terrestrial in a tall clear pot, on a wooden stand. Cymbidium goeringii is the Chinese spring orchid, in cultivation for more than a thousand years, prized for foliage and scent. ‘Tian Cao’ is a cream-margined selection. Repotting it turned into its own project.

# The name

• Genus Cymbidium. Olof Swartz, 1799. Greek for “little boat”, after the hollow of the lip.¹
• goeringii. For Philipp Friedrich Wilhelm Goering (1809–1876), a German collector. Reichenbach described it as Maxillaria goeringii in 1845 from Japanese material, then moved it to Cymbidium.²
• ‘Tian Cao’ (天草). Literally “heaven grass”. The two characters read Tiān Cǎo in Mandarin and Amakusa in Japanese, the name of a town on Kyushu the selection is said to come from. A Japanese shunran, then, wearing its Mandarin reading. Its cream leaf margin is a fukurin, a contrasting-edge variegation.³

One plant carries a German surname, a Mandarin reading, and a Japanese place name.

# Where it’s from

POWO maps it across China, the Himalaya, Japan, Korea, Myanmar and Vietnam.² IOSPE also lists Taiwan and the Ryukyus.⁴ A woodland terrestrial of shaded, often rocky slopes, rooting in thin humus over rock. Small ovoid pseudobulbs, linear leaves with finely toothed margins, the serration running right down the cream edge.

# The spring orchid

Chunlan (春兰) in Chinese, shunran (春蘭) in Japanese, both “spring orchid”. It is among the longest-cultivated of the Chinese cymbidiums, grown in the guolan (国兰, “national orchid”) tradition for fragrance and leaf form rather than display.⁵ The flower is plain. Usually one per scape (rarely two or three), pale yellow-green veined purple-brown, held low among the leaves, out in winter and early spring.⁴ The scent does the work, variously described as jasmine, lily-of-the-valley, or lemon. Hundreds of named selections exist, the dwarf, the lotus-petalled and the variegated among the most prized.

# The repot

Orticola, this May, from Piante Pazze. It came in a black nursery pot. I grew it on for a month, then repotted, and found some roots had rotted under the surface, the kind of thing a black pot hides until it spreads. New root tips were pushing too, and two new growths.

The new pot is a clear-plastic Chinese cymbidium pot, tall and narrow, 135 mm at the rim, the walls pierced with holes. Around €10 for five off AliExpress, and not something I could find in Europe. The shape fits the deep, fleshy cymbidium roots, and the holes and clear wall give drainage, air, and a window on roots and moisture.

Substrate from Geosism, all sieved first.⁶ A startling amount of dust, so do it outside with a mask. Three grades, coarse to fine, bottom to top:

• 10 mm kiryuzuna at the bottom, a hard iron-rich volcanic sand, sharp-draining and slow to break down.
• a 2–5 mm bonsai mix in the middle, mostly akadama with kiryuzuna and hyuga pumice.
• 1–2 mm kanuma on top, an acidic pumice that holds water.

The kanuma doubles as the water gauge. It pales as it dries, darkens when wet, and the clear wall shows the condensation low in the pot. I water through every 3–4 days, once the top kanuma has gone dry and that condensation is fading.

On the rim, moss off a west-facing asphalt car park in Genoa, the kind that bakes in afternoon sun and survives, so it should take a sunny windowsill. Washed, then dipped in tebuconazole. A few fungus gnats hatched out of it, but a couple of days in filtered open-air sun cleared them.

# Growing it

• Cool-growing terrestrial. Bright light, not scorching sun. On the floor at a south-facing door-window through summer, then outdoors from September until late spring.
• A cold winter rest is not optional. Flower buds need roughly 5–10 °C, or they abort.⁷ The Genoa winter, spent outdoors, delivers it.
• Water by the kanuma-and-condensation cue, every 3–4 days in growth. The grit drains hard and fast. Cymbidium roots rot wet.
• Inorganic mix, perforated pot, airy pseudobulbs, all for air and drainage.

# Links

• POWO — Cymbidium goeringii. Accepted name, authority, distribution.
• IOSPE — Cymbidium goeringii. Jay Pfahl; morphology, range, scent, cultivation.
• Yang et al. (2019), BMC Genomics. The low-temperature requirement for flowering.
• New World Orchids — ‘Tian Cao’ 天草. Notes on the Amakusa selection.
• Piante Pazze. Marco Toffoletti’s nursery near Udine, hardy outdoor orchids. Where this plant came from.

Species of the week is a rolling series. Past entries under the species-of-the-week tag; per-species page with provenance + photos at /collection/species/cymbidium-goeringii-tian-cao/.