Heidi Cardenas is a freelance writer and gardener in Lake County, Illinois, with a background in human resources. She has written about gardening for various online venues and enjoys The Herb Companion’s valuable resources.
St. John’s wort (Hypericum perforatum), also called chase-devil or klamath weed, is an herbaceous perennial shrub native to Europe, Asia, India and North America. It has yellow-green or bluish green oblong leaves that grow opposite each other on stiff stems and very pretty yellow five-petalled flowers spring through mid-summer.
St. John's wort flowers are yellow with five petals.
Photo by H. Zell/Courtesy Wikimedia Commons
Its sap is reddish colored and the flowers turn dark red if rubbed between the fingers. It is said to represent the blood of St. John the Baptist. Its flowering date, June 24th, is St. John’s birthday. The herb has a strong odor like turpentine
St. John’s wort grows up to three feet high and spreads through extensive rhizomes. It is considered invasive and weedy in some areas, becoming a noxious weed that crowds out native plants. It is dangerous to livestock if ingested. It is not a profuse seeder, dispersing seeds lightly when seedheads are dry. It has an upright growth habit, with woody stems on mature plants. The herb can be grown from seed, which germinates better when soaked overnight before sowing, but grows very easily from cuttings and divisions of rhizomes with plantlets. St. John’s wort requires full sun or bright, filtered light. It grows in any soil type and is very drought-tolerant, reviving quickly even after severe wilting.
This herb has analgesic, anti-inflammatory, astringent, painkilling and sedative properties. It has been used as a folk remedy for bladder ailments and bedwetting, shingles, gout, swellings, stomach problems, worms, uterine and menstrual cramping, skin conditions, insomnia and depression. The plant is used in tinctures, teas and powdered applications using dried leaves. Tea made from the flowers relieves jaundice, chest congestion and rheumatic pain. The plant contains hypericin, a glycoside (a sugar bound to a chemical) with a red tint, an active compound in the plant. The herb is being researched for the treatment of AIDS. If you grow it in your garden and want to use it to de-stress after a tough day at work or during a difficult emotional time, pick fresh leaves and dry them in the sun for a week or so to use for tea. You can make a tincture to use as drops under the tongue by steeping fresh leaves in 100 proof Vodka for two weeks. A poultice made with fresh leaves blanched in boiling water and wrapped in wet gauze placed on aching joints relieves pain and discomfort.
St. John’s wort is an attractive, interesting herb to grow in the garden or landscape for its many medicinal properties and pretty flowers, although it should be contained so it doesn’t get out of control.