White Horehound is a flowering, perennial, deciduous herb or shrub in the mint family that is native to Europe, Asia and Africa. It has naturalized in much of Canada, North and South America. It spreads slowly and at maturity (in 2 to 5 years), it can reach a height of 2 feet with an equal width. The bloom season is long with flowers appearing from June to November. If the plant is cut back after flowering it will normally produce a second crop of leaves. The fresh leaves have a musky smell that fades once the plant is dried. White Horehound is easy to grow and prefers full sun in sandy, dry soil with an acidic to neutral pH. Although it can tolerate moist or poor soil. It can be weedy and is usually found in disturbed and overgrazed areas. Livestock tend to ignore it and eat other plants around it, which causes the spread of the weed. In summer through fall, clusters of small white flowers in dense whorls around the upper stem in the leaf axils.and attract pollinators. The leaves are fragrant, crinkled and gray-greenwith downy hairs. White Horehound has long been used as a folk medicine and the leaves are used to produce a number of drinks, from cold remedies to ale. The plant is harvested as it comes into flower and can be used fresh or dried. White horehound is also a good companion plant for growing near tomatoes. It is not generally used in the perennial garden. Diseases, Insect Pests, and Other Plant Problems: No significant diseases or insect pests. Weedy
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.