Common Name: Japanese Quince

General Information

Chaenomeles speciosa is a thorny, wide-spreading, deciduous shrub. It forms a dense tangle of interlacing, more or less spiny branches, growing up to 3 metres tall and usually around twice as wide[, ]. The plant will often produce suckers, and can form thickets[].
The plant is harvested from the wild for use as a food and medicine - it is sometimes sold in local markets. A commonly used medicinal herb in China, it is sometimes cultivated for its fruit. The plant is also often grown as an ornamental, where it can be used as a ground cover and hedge.

Known Hazards

Although no specific information has been seen, the seed is likely to contain cyanogenic glycosides. When injested, these compounds break down in the digestive tract to release cyanide. Used in small quantities in both traditional and conventional medicine, this exceedingly poisonous compound has been shown to stimulate respiration, improve digestion, and promote a sense of well-being[]. It is also claimed by some to be of benefit in the treatment of cancer - though this claim has been largely refuted.
In larger concentrations, however, cyanide can cause gasping, weakness, excitement, pupil dilation, spasms, convulsions, coma and respiratory failure leading to death[].
The levels of toxin can be detected by the level of bitterness:- sweet almonds, for example, contain only very low levels of it and are safe to eat in quantity, whilst bitter almonds (which are used as a flavouring in foods such as marzipan) contain much higher levels and should only be eaten in very small quantities. Great caution should be employed if the taste is moderately to very bitter[].

Botanical References

Range

E. Asia - China. An occasional garden escape in Britain[].

Habitat

Long cultivated, its natural habitat is now obscure.

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	2.50 m
Pollinators	Bees
Cultivation Status	Wild

Cultivation Details

Chaenomeles speciosa is very cold-hardy, tolerating temperatures down to about -25°c when dormant[]. It succeeds in most temperate climates but does, however, require a hot summer in order to fully ripen its fruit[].
The plant is easily cultivated in any reasonably good soil[, ]. Prefers a deep, moist, well-drained loam[]. Grows well in heavy clay soils. Tolerates full shade but requires a sunny position for best fruit production[, , ]. Becomes chlorotic on very alkaline soils[]. Tolerates atmospheric pollution[].
In areas with cool summers that plants can be grown against a sunny wall, which will help to ripen the fruit[].
A very ornamental plant[], there are many named varieties developed for their ornamental value[, ].
Plants bloom on old growth. Avoid heavy pruning, generally only removing weak growth and diseased wood. If growing against a wall, prune to shape as needed immediately after flowering in order to stimulate growth of flowering spurs which will improve bloom for the following year - although this will reduce fruit production for the current year[].
Closely allied to Chaenomeles japonica[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

Fruit - cooked[, , ]. Very harsh and acid raw but fragrant when cooked[, ]. Used for jams, jellies etc and as a flavouring with cooked apples[, ]. The yellow or yellowish-green, globose or ovoid fruit can be 40 - 65mm long and 65mm wide[, ].

Medicinal

Mugua is a Chinese traditional medicine derived from the fruits of Chaenomeles species. Whilst Chaenomeles speciosa is the species most commonly mentioned in the literature for its medicinal properties, in practice the fruits of all species in the genus are used interchangeably. Modern research has supported this and, indeed, shown that some of the other species actually have higher antioxidant value[].
The fruit is analgesic, anti-inflammatory, antimicrobial, antioxidant, antispasmodic, astringent, digestive and hypoglycaemic[, , ]. A decoction is used internally in the treatment of a wide range of conditions, including nausea, joint pains, rheumatoid arthritis, hepatitis, asthma, common cold, cholera and associated cramps[, , , ].
The fruit contains polyphenols, flavonoids, triterpenes and proanthocyanidins which have been shown to have a strong antioxidant activity[]. Antioxidant compounds such as these have been shown to protect against
cardiovascular diseases and also exhibit anti-tumour, antimicrobial, anti-adhesive, and anti-inflammatory effects[]

Agroforestry Uses:

Plants can be grown as a medium sized hedge[, , ].
Some cultivars, such as 'Jet Trail' are suitable for ground cover[].
A good bee plant, flowering early in the year and providing pollen and nectar[].

Other Uses

None known

Propagation

Seed - best sown as soon as it is ripe in a sheltered position outdoors or in a cold frame[]. Sow stored seed in late winter in a greenhouse[]. Germination usually takes place within 6 weeks[]. Prick out the seedlings into individual pots as soon as they are large enough to handle. If well grown, these seedling can be large enough to plant out in the summer, but give them some protection in their first winter. Otherwise plant them out in late spring of the following year[].
Cuttings of half-ripe wood, mid summer in a frame[]. Easy[].
Cuttings of mature wood of the current year's growth, late autumn in a cold frame.
Layering in late spring or in autumn. This is a sure and easy method, though it takes 12 months[, ].