Common Buckthorn

Rhamnus cathartica

Physical Characteristics

Rhamnus cathartica is a deciduous Shrub growing to 6 m (19ft) by 3 m (9ft). See above for USDA hardiness. It is hardy to UK zone 3 and is not frost tender. It is in flower from May to June, and the seeds ripen in October. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Insects. The plant is not self-fertile. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry or moist soil.

Distribution

Europe, including Britain, from Scandanavia south and east to N. Africa and W. Asia.

Habitats

Woodland Garden Sunny Edge; Dappled Shade; Shady Edge; Hedge;

Edible Uses

None known

Medicinal Uses

Cathartic Depurative Diuretic Laxative Purgative Both the bark and the fruit of common buckthorn have been used for their purgative effect upon the body, however they can be rather violent in their action and so are rarely used in human medicines[244]. The berries, harvested when fully ripe, are cathartic, depurative, diuretic, laxative and violently purgative[1, 4, 9, 19, 46, 61, 218, 238]. About 8 - 15 of the mature fruits, chewed before breakfast, are a strong and effective laxative for adults, they should not be used by children[9]. An infusion of the not quite mature fruits is gentler in its action[9]. Use with caution, in large doses the fruit can cause vomiting and violent diarrhoea[9, 21]. The German Commission E Monographs, a therapeutic guide to herbal medicine, approve Rhamnus cathartica for constipation (see [302] for critics of commission E).

Known Hazards

The fruit is purgative but not seriously poisonous[186]. Other parts of the plant may also be poisonous[10, 19, 76, 186]. Adverse effects: Diarrhoea, weakness. Urine may turn dark yellow or red which is harmless. Possible body potassium loss if used for more than 10 consecutive days [301].