Herb: Thoroughwort

Latin name: Eupatorium perfoliatum

Family: Compositae

Medicinal use of Thoroughwort:

Thoroughwort is one of the most popular domestic medicines in North America where it is used in the treatment of influenza, colds, acute bronchitis, catarrh and skin diseases. It has been shown to stimulate resistance to viral and bacterial infections, and reduces fevers by encouraging sweating. The plant, however, should be used with some caution since large doses are laxative and emetic and the plant might contain potentially liver-harming pyrrolizidine alkaloids. The leaves and flowering stems are antispasmodic, cholagogue, diaphoretic, emetic, febrifuge, laxative, purgative, stimulant, vasodilator. A hot infusion of the dried leaves and flowers is used as a very effective treatment to bring relief to symptoms of the common cold and other similar feverishness - it loosens phlegm and promotes its removal through coughing. This herb is practically unequalled in its effectiveness against colds. It is also used in the treatment of rheumatic illness, skin conditions and worms. The leaves and flowering stems are harvested in the summer before the buds open, and are dried for later use. A homeopathic remedy is made from the fresh plant, harvested when it first comes into flower. It is used in the treatment of illnesses such as flu and fever.

Description of the plant:


120 cm
(4 feet)

July to

Habitat of the herb:

Wet woods, scrub, fens and damp grassland. Sandy soils in Texas.

Propagation of Thoroughwort:

Seed - sow spring in a cold frame and only just cover the seed. Prick out the seedlings into individual pots when they are large enough to handle and plant them out into their permanent positions in the summer. Division in spring or autumn. Very easy, the clumps can be replanted direct into their permanent positions.

Cultivation of the herb:

Wet woods, scrub, fens and damp grassland. Sandy soils in Texas.

Known hazards of Eupatorium perfoliatum:

None known

Plant information taken from the Plants For A Future.