100 White HOREHOUND Marrubium Vulgare Herb Flower Seeds BLOOM TIME: Spring HARDINESS ZONE: 4 - 8 PLANT HEIGHT: 18 - 24" . . . PLANT SPACING: 10" LIGHT REQUIREMENTS: Sun . . . SOIL / WATER: Average - Dry Horehound has white flowers and leaves whose underside are covered in white fuzz. It is a member of the mint family is used in the making of teas, candies, ale, cough syrup, and cough drops.