I love tansy. I love its ferny foliage and its cheery yellow flowers. I love that it spreads all over my garden. You say “invasive”, I say “free plants!” I love that it is so tough that it will grow almost anywhere so I can use it to fill in those spots where nothing else will grow.
Tansy is native to temperate Eurasia (Europe and Asia). It has been grown and used throughout history. The ancient Greeks were the first to grow it for its medicinal properties. In the Middle Ages, it was used as a strewing herb thanks to its insect repellent properties. Later it was used in Lenten cakes to commemorate the bitter herbs eaten by the Israelites.
Tansy has long been considered necessary in herb gardens because of its versatility. It was among the plants that colonists brought with them to the New World. It then escaped from their gardens and became naturalized in the landscape. Tansy has been used to treat worms, induce abortions, repel insects, prevent food spoilage and as a dye. It has even been used in burials to preserve bodies.
In modern times it is used in companion planting. It is very effective in repelling the Colorado Potato beetle. The dried foliage is placed along baseboards keeps ants out of the home. Tansy flowers can be dried and used in floral arrangements.
Tansy is easily grown from seed. Mature plants reach three feet in height. Once established, they spread via underground runners as well by reseeding themselves in your garden. Tansy prefers a sunny spot, but can tolerate some shade. It requires very little care and will grow in most garden soils. It is drought tolerant and disease resistant. The perfect weed!
Tansy is considered a toxic plant. Do not handle the plants if you are pregnant as it can cause a miscarriage. Do not plant it where children or pets can reach it. If eaten, emergency medical treatment is required.
Tansy has had a place in our gardens for centuries. No longer used medicinally, it is still important for its insect repellent qualities and use in dried floral arrangements. And some of us grow it simply for its beauty.