Homiclub
Chinese Toon
Type
Trees & Vines
Difficulty
Moderate
Season
Spring
Sowing
Plant a sapling
Trees & Vines

Chinese Toon

Toona sinensis

Sulfur-bearing volatiles · the red spring shoot of a tree

Chinese toon is a tree grown for the red shoots that push out in spring. In Korea those shoots are called gajuk-namul, which causes constant confusion at market with the tree of ailanthus, Ailanthus altissima, an unrelated species with a similar-sounding name. The shoots stay tender from the middle of April into May, only until the leaflets open out; after that the stalks turn stringy. The aroma is strong, so they are blanched and dressed, brushed with a thin rice-flour batter and dried into crisps, or packed into gochujang as a long-keeping pickle. Analyses report comparatively high nitrate in the young shoots, which is why discarding the blanching water settled in as standard practice. The Donguibogam lists the leaves in its Wood section as chunmogyeop (椿木葉), recording a bitter taste and toxicity. The root bark follows in the same entry under the alternative name gomokchang (苦木瘡), described as warm in nature. One tree at the edge of a country plot yields shoots year after year, and spring markets sell them tied in bundles.

Where It Grows

ChinaTaiwanSouth Korea
Origin Major producer Latitudes at 20–28℃ Zoom and pan to explore · temperatures are rough zonal averages
  • Origin It grows wild from northern to southern China, and the spring shoots — xiangchun — are consumed as a vegetable on a large scale. Shandong, Henan, Anhui, and Shaanxi are the producing regions. Harvest March, April, May
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  • Major producer The trees are kept cut back low so that only the shoots are harvested. Because the climate is subtropical, the harvest comes early.
  • Major producer The spring shoots are picked under the name gajuk-namul (namul refers to edible greens). Many trees are planted in southern areas such as Hadong and Sancheong in South Gyeongsang, and South Jeolla. Harvest April, May
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Native to China, the tree reached the Korean Peninsula long ago and was planted around temples and at village entrances. Eating the shoots as a vegetable is confined to China, Taiwan, and Korea; in Southeast Asia and Australia the tree was introduced for timber and landscaping, so those places are not counted as shoot-producing regions. There is no entry for it in FAO statistics.

Optimum
20~28℃
Range
10~32℃
Hardiness
Half-hardy

This is a tall deciduous tree that likes warmth. Fully grown trees can withstand winter cold, but young trees easily suffer frozen branch tips, so in Korea it is planted from the central region southward. Spring temperatures decide when the shoots emerge, and if a late frost strikes, the year's first shoots are lost.

Harvested 3–5 years after planting. Three or four years must pass after planting a seedling before shoots worth picking appear. The month of planting and the month of picking do not fall in the same year. Once the tree is established, the shoots are picked every spring.

In Korea Central Korea and south

Many trees are planted in Hadong and Sancheong in South Gyeongsang, in South Jeolla, and in the southern part of South Chungcheong. From the central inland region northward, the branches freeze in winter and the following year's shoots come out small.

How to grow

Light
Half a day of sun or more. In deep shade the shoots come up thin and the scent is weak
Soil and depth
Free-draining soil at least 40cm deep. Avoid spots where water sits
Spacing
Three to four metres between trees. It grows large, so keep it away from walls and windows
Watering
Keep it from drying out through the first year only. Once rooted it largely carries itself on rainfall
Feeding
Work compost around the base in November or December after leaf fall. Heavy nitrogen draws the shoots up soft and thins the aroma
Harvest
April and May. Cut at the base when the shoot is about a hand-span long and the leaflets are still folded. Do not strip every shoot — leave several at the top to build the tree

What makes the difference. Blanch picked shoots briefly in boiling water and rinse cold before use. Discard the blanching water, and never eat them raw

Why this one is harder. It grows into a large tree, so in a small plot the shade becomes a problem within a few years. New stems also rise from the roots, so set it well back from walls and boundaries when planting

Common problems

  • Aphids You will see Colonies on the tips of the new red shoots What to do Wash off with a jet of water; if it recurs, use an egg-yolk oil spray. Observe pre-harvest intervals where shoots are to be picked
  • Fall webworm You will see A white webbed nest at a branch tip in summer, the leaves inside reduced to a mesh What to do Cut out the whole branch while the nest is small and bag it for disposal. Later the caterpillars scatter and are hard to catch
  • Root rot You will see Shoots fail to appear in spring, or start and then wilt What to do Avoid spots where water sits and raise the bed. Dig out a rotted tree and do not replant in the same place

This page describes how a crop is grown and used. It does not claim health effects for any food, nor is it intended to prevent or treat disease. Component and study notes are references only and do not mean the same result occurs in people. Consult a medical professional about health concerns.

Health Benefits

What the Donguibogam records — chunmogyeop (椿木葉). The Donguibogam lists Chinese toon leaves in its Wood section as chunmogyeop (椿木葉). It records a bitter taste and states that the leaf is toxic. The root bark is treated in the same entry under the alternative name gomokchang (苦木瘡) and given a warm nature. The entry quotes the Bencao. This is a historical medical record and differs from modern medical judgment.

The aroma and its volatile oils. That the heavy scent of toon shoots comes from volatile oils has been addressed in compositional analysis. That the scent fades and the stalk coarsens as the shoot opens is an observation confirmed repeatedly in growing and cooking.

Nitrate and blanching. Analyses report comparatively high nitrate in young toon shoots, with the same work reporting that much of it passes into the water on blanching. These are compositional analyses and have nothing to do with preventing or treating disease.

Nutrition

  • Sulfur-bearing volatiles (carry the aroma of the young shoot) — volatile compounds behind the distinctive scent
  • Flavonoids (quercetin and kaempferol glycosides) (present in the leaves) — flavonoid glycosides identified in the foliage
  • Nitrate (reported comparatively high in young shoots) — a water-soluble compound that leaches out on blanching
  • Dietary fibre (rises as the leaf stalk thickens) — the tissue that coarsens once the shoot opens out

It has to be blanched Toon shoots are strongly scented and thick-stalked, so they go into boiling water first. Blanch briefly in salted water, rinse cold, and throw the blanching water away. Analyses report comparatively high nitrate in the young shoots, which is why discarding that water settled in as standard practice.

The volatile oils The heavy scent released when a leaf is rubbed comes from volatile oils. As the shoot opens and the weather warms, the scent fades and the stalk toughens. Picking time governs aroma and texture together.

Flavonoids Analyses identify quercetin- and kaempferol-type glycosides in the leaves. This entry stays with the compositional record.

What drying changes Toon dried into crisps has lost its water, so weight for weight the composition figures read very differently. Check whether a table is on a fresh or dried basis before comparing numbers.

Pairings

○ Gochujang and sesame oil — Shake the blanched shoots dry and dress them with chilli paste and sesame oil. The heat of the seasoning carries the heavy aroma. Split the thick bases lengthwise so the pieces match. Chili Pepper (Gochu)

○ Rice-flour batter — chamjuk bugak — Brush the shoots with a thin glutinous rice batter, dry them in the sun, then fry. It is the old way of stretching a one-week crop across the year. Keep them out of the rain while they dry.

○ Gochujang pickle — Blanch, dry off the surface water, and bury the shoots in chilli paste. After about a month the aroma has moved into the paste and the pickle goes to the table. Use dry chopsticks to lift them out. Chili Pepper (Gochu)

△ Confusion with tree of heaven — The spring shoots of Chinese toon are eaten, but Ailanthus altissima, a Simaroubaceae tree carrying a near-identical Korean name, is not. Ailanthus leaves smell foul when rubbed and bear gland-tipped teeth near the leaflet base; they are not used as a vegetable. Chinese toon has evenly fine teeth along the leaf margin and red new shoots. If you are not certain, do not pick.

△ Never eaten raw — Toon shoots are blanched, not eaten raw. The old text itself recorded a bitter taste and toxicity, and discarding the blanching water remains the basic handling today. Keep the blanching short — a long boil takes the aroma with it.

△ Trees on roadsides and car park edges — Do not pick from trees standing along traffic or at the edge of a car park. Exhaust and spray reach those spots, and the shoot is a tight fold of leaflets that does not rinse clean between the layers.

Varieties

  • Chinese toon (sapling) — The tree whose spring shoots are eaten. Rub a leaf and the scent is strong
  • Tree of heaven (distinction) — A different tree (Simaroubaceae) with a confusingly similar Korean name. Its shoots smell foul and are not used as a vegetable

Source: Donguibogam, Wood Section 椿木葉 · Korea National Arboretum, Korean Plant Names Index