Common Name: Western Labrador Tea

General Information

Rhododendron columbianum is an evergreen shrub or small tree growing from a rhizomatous rootstock; it can grow up to 2 metres tall[].
The plant is harvested from the wild for local use as a food and medicine

Known Hazards

Plants contain a narcotic toxin called Ledol - this is a sesquiterpene that can cause cramps, paralysis, and delirium. Ledol is also said to have various beneficial effects if consumed in the correct dosage and it is said that, when ingested as a herbal tea, it only causes problems if the leaves are cooked for a long period in a closed container[].

Botanical References

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Range

Western N. America - British Colombia and Alberta, south to California and Colorado

Habitat

Bogs, swamps, stream margins, sometimes on well-drained sites; at elevations from sea level to 3,500 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	1.50 m
Cultivation Status	Wild

Cultivation Details

Rhododendron columbianum is hardy to about -15°c[]. Although cold-tolerant when dormant, the flowers and young growth of Rhododendrons are very susceptible to damage by late frosts in regions where these are likely to occur after new growth has commenced in the spring[].
Requires a lime-free loam or peaty soil[, ]. Prefers a moist humus-rich acid soil in shade or semi-shade[]. Plants flower more freely when grown in a sunny position. Plants grow better if they have certain fungal associations in the soil. The best way of providing this is to incorporate some soil from around well-growing established plants into the soil for the new plant[].
The leaves are covered in tiny spots or glands from which a strong, resinous scent is given off[]. The flowers also have an aromatic perfume[].
Plants benefit from removing the dead flowers before they set seed[]. This prevents them putting too much energy into seed production at the expense of more flowers and leaves.

Edible Uses

Some caution is advised if consuming this plany - see the notes above on toxicity.

An aromatic tea is made from the fresh or dried leaves[, , ]. The dried leaves are often mixed with non-aromatic leaves such as comfrey[]. Some caution is advised, see the notes above on toxicity. It would be better to brew the tea in cold water by leaving it in a sunny place, or to make sure that it is brewed for a short time only in an open container.

The leaves are used as a flavouring, they are a bayleaf substitute[].

The fresh leaves can be chewed[].

Medicinal

Some caution is advised in the medicinal usage of this plant - see the notes above on toxicity.

The leaves and young flowering shoots are astringent, diaphoretic, diuretic, laxative and stomachic[].

Other Uses

The leaves are used to repel moths, mice, rats etc[].

Propagation

Seed - surface sow in a shady part of the greenhouse in late winter or early spring[, ]. Another report says that the seed is best sown in the autumn as soon as it is ripe[]. Germination is variable and can be quite slow. Prick out the seedlings into individual pots as soon as they are large enough to handle and grow the pots on in a shady frame for 18 months before planting them out into their permanent positions[].
Cuttings of half-ripe wood, 5 - 8cm with a heel, mid summer in a frame. Plant out in spring. Fair percentage[].
Cuttings of mature wood, late autumn in a frame[].
Layering in the autumn. Takes 12 months[].
Division.