The late summer months here in Canada are some of the best for outdoor activities. From picnics, playgrounds, camping, cottages, hikes, sports and swimming, July and August are traditionally when we spend the most time outside. Unfortunately, this is also when we spend the most time dealing with insects. Tansy (Tanacetum vulgare) is a common garden herb that blooms precisely on time to help with these unwanted summer visitors. An excellent natural insect repellent, tansy can be used both indoors and outdoors to deter bugs from becoming pests.
PLANT DESCRIPTION
Tansy is a perennial plant from the Asteraceae family. Standing around one to three feet tall with feathery “fern-like” leaves, this hardy plant has a lush, tropical look. In the later summer months, yellow “buttons” flower in flat-topped clusters called corymbs. Like many plants in the Aster family, tansy is very aromatic. The scent has been described as pine-like and similar to camphor. When the leaves or flowers of tansy are touched or crushed, the essential oils are released into the air. Home gardeners like to place tansy along paths and other high-traffic areas so passersby will brush against it and release the scent. This easy-to-grow herb is known to take over a garden; tansy spreads by sending out relentless underground stems called rhizomes. Time and effort are required to control growth, but fortunately, tansy does well in containers, which helps keep this invasive plant at bay.
HISTORY
Once native to Europe, tansy has been naturalized all over the world, especially in North America. Considered an invasive weed in many places, tansy is found from Nova Scotia and Ontario to Minnesota, Missouri, North Carolina, Oregon and Nevada.4 As it does well in nearly any soil condition, tansy grows in unexpected “weedy” places along roadsides, fields, and even near water. Cows and sheep have been known to eat tansy, but goats, horses, and pigs will not touch it.
The name Tanacetum comes from the Greek word athanasia, which means immortality. The association with immortality may be due to tansy’s long flowering season or from Greek mythology; Zeus gifted his cupbearer Ganymede with an immortality potion rumoured to contain tansy as a main ingredient.
According to Egyptian legends, the deity Isis is attributed with discovering the medicinal properties of tansy.
In the 16th and 17th centuries, the smell of tansy was common in English homes, even amongst royalty. Tansy was a popular strewing herb: a practice involving tossing the freshly harvested plant onto floors. The tansy would be crushed underfoot, releasing its volatile oils into the air, like an old world air freshener!
King James II even had his own royal herb strewer. Tansy’s strong smell and insect-repelling powers made it a popular herb for funerals and kitchens (especially during a time without air conditioning or refrigeration). The herb was both rubbed on the deceased and placed in the coffin to preserve the body from “corruption.”
Tansy was once also a very popular culinary herb. The English used it to flavour cakes and puddings as part of the Easter tradition. Tansy cakes, made with young leaves and eggs, were thought to “purify” the body after Lent. Tansy is sometimes included in a traditional Passover meal and is rumoured to be one of the 130 herbs in the Chartreuse liqueur formula. The leaves are said to have a peppery flavour, and were used to replace nutmeg and cinnamon when spices were harder to come by. Tansy was added (sparingly) to scrambled eggs, cakes, puddings, teas, liqueurs, salad dressings, herb butters, marinades and stuffing.
MEDICINAL PROPERTIES & INDICATIONS
The primary chemical constituent of tansy is a volatile essential oil called Thujone. In historical herbal texts, it’s referred to as “oil of tansy.” This is the same essential oil found in Wormwood (Artemesia absinthium). Unfortunately, the Thujone content varies from plant to plant and can be as high as 70 percent. This oil can be lethal in large doses, and many herbalists no longer use tansy over toxicity concerns. The internal medicinal uses discussed here are for historical reference only and not recommended unless under medical supervision.
WOUND HEALING
As a topical remedy, tansy has been in recorded use since the 14th century, when it was listed as a treatment for wounds. King’s American Dispensary (1898) mentions the herb as a popular treatment for swellings, tumours, and local inflammations. Tansy was used chiefly in the form of a Fomentation: a topical treatment where strips of cloth are soaked in a herbal extract, often a tea, and placed on affected skin. This was reported to treat tumours, scabies, eruptive skin diseases, fleas and lice. English herbalist Nicholas Culpepper (1616-1654) believed tansy would remove “freckles, sunburns, and pimples.” When added to bath water, tansy was thought to relieve sore joints, sprains, and lower fevers.
DIGESTIVE SYSTEM
NOTE: A word of caution; although safe to use topically, tansy should only be used internally under the supervision of a trained licensed professional. Well known in ancient herbal texts, medicinal uses of tansy have fallen out of favour in recent decades due to concern over its toxicity. Safer herbs with similar medicinal properties are typically recommended instead.
In the 12th century, Hildegard von Bingen, a scientist and doctor of the Church, wrote about using tansy to “dispel worms.5 King’s American Dispensary specifically recommends the seeds of the plant as the most effective for removing worms from the body.
A warm tea infusion taken in the morning and at night, while fasting, was a popular treatment for dealing with worms in children. Tansy root was also once considered a reliable remedy for gout. In small doses, cold tansy tea was used to help with dyspepsia, flatulence, and spasms in the digestive tract.
FEMALE REPRODUCTIVE SYSTEM
Tansy is considered a strong agent and can cause the onset of menses. It was once used to induce abortions, but this often proved ineffective and was potentially lethal. Tansy was also considered helpful for painful menstruation, delayed menstruation and even labour pains. Herbalist Nicholas Culpepper placed tansy leaves topically over the navel to prevent miscarriages.
CONTRAINDICATIONS & SAFETY
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NOT for inexperienced practitioners. Internal use only under medical supervision
- External use only recommended
- NOT to be used during pregnancy
- Strong emmenagogue, can bring on menstruation
- Tansy oil and tea can be LETHAL
- Signs of tansy poisoning: fast/weak pulse, spasms, foaming at the mouth, rapid breathing, dilated pupils, severe reddening of face, and paralysis
- Individuals with allergies or sensitivity to Aster plants should use caution as it may cause dermatitis
PREPARATIONS & APPLICATIONS
Due to potential toxicity, most internal uses are no longer advised. Safer herbs with similar medicinal actions are recommended instead.
OTHER USES FOR TANSY
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Grow tansy in containers and place near doorways to deter insects
- Bouquets near windows (indoors and outdoors) will repel flies
- Place in sachets with other herbs (like Elder leaves) near outdoor dining areas
- For a modern take on “strewing,” place dried sprigs under carpets
- Fresh leaves and flowers will deter mice6
- Crushed plant will make a yellowish-green natural dye
