Horehound, White (Marrubium vulgare)
Horehound, Common Horehound
About This Plant
White Horehound is an upright, bushy, perennial subshrub from the Lamiaceae, or Mint family that is hardy in USDA zones 3 – 10. It is a cool-season plant that is not frost tender and grows to about 18”-24” high. It can be found growing in cultivated or disturbed places, along roadsides, in deserts, mountains, and riparian habitats.
White Horehound has the characteristic four-sided stems of the Mint family. Its stems branch from a somewhat woody base. The entire plant is covered in dense, white, wooly hair. Its opposite leaves are wrinkled and pale green in color with coarsely toothed margins, growing up to about two inches long and one inch wide.
White Horehound flowers from about June until late into the Fall. Its small white Snapdragon-like tubular flowers are crowded into very dense, compact round clusters that form around the stem and leaf axils. The flower clusters also form at the end of all the branches forming long spikes. The calyx is also tubular with ten spine-like teeth that curve downward. The plant typically won’t blossom its first year.
The fruits of White Horehound are tiny, bur-like and egg shaped, brown or dark gray, with dark granules scattered on the surface. Each little “nutlet” contain one seed. The seeds have a small hook on them which allows them to attach to the fur of passing animals ensuring their dispersal.
The roots are rhizomatous, spreading underground stems, that send out roots and shoots.
The plant has a bitter smell when fresh. The odor diminishes as it dries, but the taste remains bitter, which is why many traditional remedies that utilize Horehound are made more palatable with the addition of sugar or honey, such as the familiar Horehound cough drops.
White Horehound was a common medicinal plant in the past, used for its effectiveness in clearing out lungs and stopping coughs. It is also thought to be one of the five bitter plants eaten during the seder feast of the Jewish Passover celebration, in remembrance of the bitterness of captivity in Egypt. In fact, the Latin name for Horehound, Marrubium, may be derived from the Hebrew word “maror”, which means “bitter juice”. The name Horehound is believed to be derived from the Egyptian god of sky and light, Horus.
There are three types of Horehound: White (Marrubium vulgare), Black or Stinking (Ballota nigra), and Water Horehound (Lycopus americanus). Both the Black and White are in the Mint family. Black Horehound is toxic in large doses and should not be consumed.
White Horehound can be grown from seed, cuttings, or division. Growing from seed is easy, but the seeds do benefit from stratification – they need a period of cold, such as going through a winter, before germinating. Seeds can be directly sown in the Fall, as the plants would do naturally, or seeds can be placed in a refrigerator for a month before being started indoors or directly planted in the Spring. Basal cuttings can be taken in late Spring. Shoots can be harvested with plenty of underground stem attached when they are about three to four inches above the ground. Pot up the shoots and keep them in light shade in a cold frame or greenhouse until they are established and plant them out in the Summer. Division can be done in the Spring with the clumps directly planted into their permanent location or potted up until established and planted out the following Spring.
The final spacing of White Horehound should be about a foot apart.
White Horehound requires full sun and prefers poor, dry, sandy soils, making it an excellent candidate for xeriscaping. It cannot grow in the shade. The plants can be cut back after flowering to produce a second crop of leaves. It is known to be a good companion plant for tomatoes, causing them to produce a more bountiful crop.
White Horehound is harvested as it comes into flower and can be used fresh or dried. It can be harvested the first year as long as you limit your harvesting to the top ⅓ of growth. From the second year on, you can cut the plants back to about four inches above the ground.
White Horehound seeds from about August to October. Once seeds are mature, stems can be cut, bundled and hung to dry and seeds collected once dried.
- Companion plant to Tomatoes
White Horehound has a bitter and pungent taste. The leaves are edible and can be used as a seasoning. It has been used in the past to flavor herb beers and liqueurs. It can be made into a mild and pleasantly flavored tea by using either fresh or dried leaves.
White Horehound has long been used for coughs and colds. It is said to cause the secretion of a more fluid mucus that can readily be cleared by coughing. It can be safely used by children as well as adults. Along with being an expectorant, it is an antiseptic, antispasmodic, diaphoretic, digestive, diuretic, emmenagogue, hepatic, stimulant, and tonic. The leaves and young flowering stems are the parts used.
As a bitter tonic, it increases the appetite and supports digestion. It is used to treat mild dyspepsia symptoms such as bloating and flatulence. Taken in large doses, it acts as a gentle purgative. The German Commission E Monographs approve of it for dyspepsia and loss of appetite. The root was used for rattlesnake bites and the powdered leaves have been used as a vermifuge. A salve was also traditionally made from the leaves, boiled in lard, that was used for wounds.
Candied Horehound was a traditional medicine made by boiling the fresh plant down until the juice was extracted, then adding sugar and boiling again into a thick consistency. This was poured into a paper case and once cooled, cut into squares and given for colds and coughs.
White Horehound can be safely consumed by children. Large doses can affect heart rhythm, blood pressure, and blood glucose. If taking medication that affects blood sugar, it’s best to avoid Horehound. It is also recommended to avoid Horehound if pregnant or breastfeeding.
White Horehound is native to all of Europe, Asia, and the northern part of Africa. It was brought to North American by European colonists and is now naturalized throughout the continent.