Tansy / Tanaceto o Palma de India

Tansy (Tanacetum vulgare) is a striking old medicinal herb with deeply divided, almost fern-like leaves and clusters of bright yellow button flowers held above the foliage. The whole plant has a strong, unmistakable aromatic scent, and once established it grows as a hardy perennial, gradually spreading through underground rhizomes and forming a substantial patch.

Tansy has a very long history in traditional herbal medicine and was particularly famous as an old worm herb, used historically for intestinal worms and digestive complaints. It was also used for cramping, sluggish digestion and menstrual complaints. This is an important plant to understand, however, because medicinal does not mean harmless. Tansy is a potent herb and can be poisonous when used incorrectly or in excessive amounts. Its aromatic oils can contain significant amounts of thujone, and the concentration can vary considerably between individual plants. It is therefore not an everyday drinking herb and should be treated as a strong traditional medicine rather than an ordinary culinary tea.

In the garden, Tansy has another wonderful role. Its tall yellow flower clusters attract an enormous amount of insect activity, bringing diversity into the garden while its dense perennial roots keep the soil occupied and covered. The aromatic foliage and distinctive flowers also make it very easy to recognize once you know the plant.

Tansy prefers plenty of sun and well-drained soil and becomes quite resilient once established. Give young plants regular moisture while they develop their roots, after which they can tolerate considerably drier conditions. It spreads through both rhizomes and seed, so plant it somewhere you are happy for it to establish a colony, or cut it back after flowering if you want to contain its spread.

Tansy is an old, powerful and fascinating medicinal plant, but it is also a good reminder that some of our strongest plant medicines require knowledge and respect. Its beautiful golden flowers may look cheerful and innocent, yet this is a plant with considerable potency.