Hardy orange (Poncirus trifoliata)

Hardy orange (Poncirus trifoliata)
Wikimedia Commons — Jebulon — Public domain

At a glance

Lifecycle
Perennial (hardy)
Exposure
Full sun
Frost limit
−28.9 °C

Cultivation

An easily grown plant, it succeeds in an ordinary garden soil. Hardy to about -15°c. The bitter orange hybridizes with Citrus species and could possibly be used in breeding programmes to produce hardier forms of oranges, lemons etc. It could also be of value in conferring disease resistance, tolerance of poorer soils and dwarfing characteristics. The flowers are produced on the previous years wood. A very ornamental plant. Plants are relatively short-lived, deteriorating after about 25 years.

Propagation

Seed - best sown as soon as it is ripe in a cold frame. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in early summer. Cuttings of half-ripe wood, June/July in a frame.

Edible uses

Fruit - cooked. A bitter and acrid flavour, but it can be used to make a marmalade, though most of this is the skin[K]. The fruit peel can be used as a flavouring. Young leaves - cooked.

Medicinal uses

The thorns are used in the treatment of toothache. The stem bark is used in the treatment of colds. The fruits contain a number of medically active constituents including flavonoids, coumarins, monoterpenes and alkaloids. The fruit, with the endocarp and seeds removed, is carminative, deobstruent and expectorant. The unripe fruit is antidiarrheic, antiemetic, antispasmodic, deobstruent, digestive, diuretic, laxative, stimulant, stomachic and vasoconstrictor.

Material uses

Used as a rootstock for Citrus species (oranges, lemons etc). The plant is very thorny and makes an excellent impenetrable barrier or hedge.

Habitat

Hedgerows.

Native range

E. Asia - C. and S. China, Korea.