Cascara Sagrada (Rhamnus purshianus)

At a glance

Lifecycle: Perennial (hardy)
Exposure: Full sun
Frost limit: −17.8 °C

Cultivation

Succeeds in any reasonably good soil in sun or partial shade. This species is hardy to at least -15°c. Closely related to R. frangula. This species is cultivated as a medicinal plant in N. America. The flowers are produced in small clusters on shoots of the current year's growth. A good bee plant. The species in this genus are notably resistant to honey fungus.

Propagation

Seed - best sown in the autumn in a cold frame. Stored seed will require 1 - 2 months cold stratification at about 5° and should be sown as early in the year as possible in a cold frame or outdoor seedbed. Prick out the seedlings into individual pots when they are large enough to handle, and grow them on in the greenhouse or cold frame for their first winter. Plant them out in late spring or early summer of the following year. Cuttings of half-ripe wood, July/August in a frame. Cuttings of mature wood of the current year's growth, autumn in a frame. Layering in early spring.

Edible uses

Fruit - raw or cooked. An extract of the bark, with the bitterness removed (by drying?) is a common flavouring for soft drinks, baked goods and ice cream.

Medicinal uses

Cascara sagrada is widely used as a gentle laxative that restores tone to the bowel muscles and thus makes repeated doses unnecessary. The bark also has tonic properties, promoting gastric digestion and appetite.

Material uses

A green dye is obtained from the bark. Plants are sometimes grown in America as an ornamental hedge. Wood - light, soft, not strong. Used for making the handles of small tools.