Loquat

Eriobotrya japonica

Carotenoids · a southern evergreen that flowers in winter

The loquat is an evergreen fruit tree grown in Korea's warm south. It runs on the opposite calendar to most fruit trees: the flowers open between October and December, the young fruit overwinters, and the crop ripens the following May and June. Further north it will not come through winter outdoors, so the practical route is a large pot moved indoors or onto a glazed balcony for the cold months. The Donguibogam lists it in the Fruit section as 枇杷葉, giving the leaf a neutral nature and a bitter taste, though some call it sweet, with no toxicity. The same entry instructs that the yellow down on the underside of the leaf be wiped away completely with a cloth before use, because down left behind irritates the throat.

Year-Round Calendar

Sowing

Harvest

Where It Grows

Origin Major producer Latitudes at 15–25℃ Zoom and pan to explore · temperatures are rough zonal averages

Origin Southern China is the plant's place of origin and produces more than nine tenths of the world's crop. Fujian, Zhejiang, Jiangsu and Sichuan are the growing regions. Harvest April, May
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Major producer Spain is the largest producer outside China. The centre of production is Callosa d'en Sarrià in Alicante, in the south-east. Harvest April, May
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Major producer Grown along the Mediterranean and Aegean coasts. Harvest April, May
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Major producer The growing regions are mild coastal areas such as Nagasaki and Chiba. Harvest May, June
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Major producer Grown in the mild-winter belt of northern Punjab.

The loquat originates in southern China and spread by way of Japan to the Mediterranean and the New World in the 19th century. Despite the japonica in its scientific name, it is not native to Japan. Production today is concentrated on mild coasts where winter temperatures rarely drop below freezing, and because most growing regions lie in the Northern Hemisphere, their harvests overlap in spring.

Optimum: 15~25℃
Range: 5~30℃
Hardiness: Half-hardy
Day length: Not applicable

Loquat is an evergreen fruit tree that flowers in winter, so the winter minimum temperature decides where it can be grown. The tree itself withstands roughly -10℃, but the flowers freeze at about -3℃ and young fruit at about -2℃. Mild coastal areas with an annual mean temperature of 15℃ or above suit it best. Flowering is triggered not by day length but by the pattern of falling temperatures in autumn.

Harvested 3–5 years after planting. Grafted saplings bear fruit three or four years after planting; trees raised from seed take six or seven. On top of that, the flowers open between October and December and the fruit ripens the following May or June, so the year of flowering and the year of picking are not the same.

In Korea Jeju and the south coast

The growing regions are Wando and Geomundo in South Jeolla, Namhae in South Gyeongsang, and Jeju. Flowers that open between October and December overwinter (surviving on the tree through the cold season) and ripen the following May or June, so in central Korea, where winter lows often fall below -5℃, fruit is hard to obtain outdoors.

How to grow

Light: Six hours of direct sun or more. A sheltered south-facing wall beats open ground
Soil and depth: Free-draining soil at least 40cm deep. Start a potted tree in a container 40cm across or wider
Spacing: Four to five metres between trees in the ground. One tree per pot, repotted every two or three years
Watering: Water a pot thoroughly once the surface dries. Drought while the fruit swells in April and May leaves small fruit
Feeding: Feed with organic matter in February before growth starts, and again in June once picking is over. Too much nitrogen pushes leaf at the expense of fruit
Harvest: May and June. Pick when the skin has turned fully orange and the fruit parts with slight pressure. It will not ripen further off the tree, so ripen it on the tree. The skin is thin and marks easily, so hold the stalk

What makes the difference. Fruit sets in trusses; thin each one to three or four. What is left grows larger and disease drops off

Why this one is harder. Flowers open between late autumn and midwinter, and below minus five degrees the flowers and young fruit freeze. Outside the warm south, the reliable route is a pot brought into a space held above freezing for the winter

Common problems

Scale insects You will see White scabs along stems and leaves, with sooty black spreading beneath them What to do Scrub them off with a brush and apply a winter horticultural oil. Thin crowded branches to open up airflow
Grey mould (Botrytis) You will see Soft brown patches on ripening fruit, spreading under a grey fuzz What to do Through wet spells, pick off affected fruit at once. Thin the trusses and bag them so fruit does not touch
Birds You will see Only the fruit that has begun to colour is pecked What to do Bag whole trusses or throw a net over the tree. Do it just before the colour comes up

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 — nature, taste and preparation. The Donguibogam lists the plant in the Fruit section as 枇杷葉. The leaf is given a neutral nature and a bitter taste, though some call it sweet, with no toxicity. The fruit is recorded separately as cold in nature, sweet in taste and free of toxicity. It grows in the south, the entry says, the tree standing a little over three metres, the leaves as large as a donkey's ear with down on the back, and the leaves are gathered in the fourth lunar month and dried in the sun. Before use they are passed over a flame and the yellow down wiped away completely with a cloth. This is a historical medical record and differs from modern medical judgment.

Pigment composition of the flesh. Analyses report that the orange of loquat flesh comes from carotenoids including β-cryptoxanthin and β-carotene. The same work found wide differences in total pigment between cultivars and stages of ripeness. This concerns colour and composition and has nothing to do with preventing or treating disease.

Cyanogenic glycoside in the seed. Amygdalin has been reported in loquat seeds by repeated analysis, alongside published warnings from food authorities against consuming ground-seed products. This is safety information, not a statement of benefit.

Nutrition

Carotenoids (β-cryptoxanthin, β-carotene) (the orange pigment of ripe flesh) — fat-soluble pigments that give the fruit its colour
Sorbitol (a sugar alcohol in the flesh) — part of the fruit's sweetness
Triterpenes (ursolic and oleanolic acid) (found in leaf and skin) — triterpene compounds reported from the leaf
Amygdalin (in the seed and unripe fruit, and reported at low levels in the leaf) — a cyanogenic glycoside; the seed is not eaten

The carotenoids behind the orange The orange of ripe loquat flesh comes from carotenoids such as β-cryptoxanthin and β-carotene. These pigments are fat-soluble, and analyses report higher levels in deeper-coloured flesh. Fruit still merely yellow has not finished laying the pigment down. Letting the colour finish on the tree serves flavour and colour alike.

Sugars and acids Loquats run around 10 to 13 brix, with malic and citric acid supplying the tartness. The share of sorbitol among the sugars is higher than in most fruit. Sorbitol is absorbed slowly, so a large helping at one sitting can leave the gut unsettled. More than ten at a time is not a habit worth forming.

The seed and amygdalin Loquat seeds and unripe fruit contain amygdalin, a cyanogenic glycoside, and it is reported at low levels in the leaf as well. The seed carries by far the most; the leaf carries far less. Broken down in the body it releases cyanide, so the seed is spat out rather than eaten. Powders and extracts made by grinding the seed have drawn repeated warnings from food authorities in Korea and abroad. None of this applies to eating the ripe flesh.

Triterpenes in the leaf Loquat leaves are reported to carry triterpenes such as ursolic and oleanolic acid alongside flavonoids. Drying the leaves for tea is a long-standing habit in the south. The yellow down on the underside floats in the cup and catches in the throat, so wipe it off with a damp cloth before drying. Amygdalin is also reported in the leaf at low levels, so brew the tea without any seed in the pot and keep the infusion weak. This entry stays with the compositional record.

Pairings

○ Lemon and sugar — poached loquat — Peeled loquat browns within minutes. Dropping the pieces into lemon water and then poaching them with sugar holds the colour. Take every seed out before the pan goes on.

○ Yoghurt and cream — Low acid and a mild aroma make loquat an easy match for dairy. Halve the fruit, lift out the seeds and lay it on as it is. The skin peels away by hand.

○ Dried leaf tea — Dry the leaves in the shade, shred them and steep. Wiping the down off the underside comes first. Two or three light infusions drink better than one strong one.

△ The seed — not to be eaten — Loquat seeds contain amygdalin and are not chewed or ground for eating. Powders and extracts made from the seed are a category food authorities in several countries have warned against consuming. Halve the fruit and take the seeds out before giving it to a child, so nothing is swallowed whole. The flesh is not at issue.

△ Unripe fruit — Fruit still showing green in the skin is astringent and sharply sour, and amygdalin remains in the flesh as well. Loquats do not ripen after picking, so leave them until the orange has come up fully on the tree. Underripe fruit set aside to soften only goes soft.

△ Rose-family allergy and leaf down — Loquat belongs to the rose family, like apple and peach. Anyone who gets an itching or swelling mouth from those fruits should try a single one first and see. When handling leaves, airborne down irritates throat and eyes, so wipe it away with a damp cloth as you work.

Varieties

Mogi (茂木) (sapling) — A small-fruited line. Modest in size, high in sugar
Tanaka (田中) (sapling) — A large-fruited line, reckoned the hardier of the two common ones
Obusa (大房) (sapling) — A heavy-fruited line planted outdoors in the far south
Seedling loquat (seed) — Raised from a pip. Fruit quality comes out uneven and it takes several years to bear

Source: Donguibogam, Fruit Section 枇杷葉 · Rural Development Administration (Nongsaro)