Herb: Water Horehound

Latin name: Lycopus americanus

Family: Labiatae

Medicinal use of Water Horehound:

The whole plant is used as an astringent, hypoglycaemic, mild narcotic and mild sedative. It also slows and strengthens heart contractions. The plant has been shown to be of value in the treatment of hyperthyroidism, it is also used in the treatment of coughs, bleeding from the lungs and consumption, excessive menstruation etc. It should not be prescribed for pregnant women or patients with hypothyroidism. The plant is harvested as flowering begins and can be use fresh or dried, in an infusion or as a tincture.

Description of the plant:


50 cm
(1 foot)

July to

Habitat of the herb:

Low moist or wet places.

Edible parts of Water Horehound:

Root - raw or cooked. This contradicts with the report in that the plant does not form tubers on its rhizomes.

Other uses of the herb:

The juice gives a permanent colour to linen and wool and does not wash out. The colour is not mentioned.

Propagation of Water Horehound:

Seed - sow spring or autumn 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 their first year. Plant them out into their permanent positions in early summer. Division in spring or autumn. Larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.

Cultivation of the herb:

Low moist or wet places.

Known hazards of Lycopus americanus:

None known

Plant information taken from the Plants For A Future.