Feverfew

Feverfew (Tanacetum parthenium) is a daisy-family herb originating in the Balkans, now naturalised worldwide. It produces a profusion of small white or lime-green button-like flowers on branching stems 45–90 cm tall. Valued both as a medicinal herb and a productive cut flower, it thrives in well-drained soil with good light. In Nordic conditions it behaves as a hardy annual or short-lived perennial, self-seeding freely once established.

Growing

Start seeds indoors 8 weeks before outdoor temperatures stay reliably above 5 °C at night. Sow onto the surface of moist compost and press lightly — seeds need light to germinate, so cover with no more than 2 mm of fine vermiculite or grit. Maintain a soil temperature of at least 10 °C; germination occurs in 10–21 days. Prick out seedlings into individual cells once the first true leaf appears. Harden off over 7–10 days once overnight air temperatures hold above 5 °C, then transplant at 30 cm spacing into a sunny or lightly shaded, well-drained site.

Care

Water consistently during establishment; once rooted, feverfew tolerates short dry spells but performs best with regular moisture. Apply a balanced liquid feed every 2–3 weeks once stems begin to elongate. Deadhead or cut stems back to a basal fork after the first flush of blooms to encourage further branching and prevent excessive self-seeding. No staking required for standard-height plants; very tall ornamental varieties may need light support in exposed positions.

Harvest

Cut stems when 50–70 % of the flower buds on a branch have opened — at this stage blooms are fully expressive and stems condition well. Use sharp scissors or snips and cut to a side branch or leaf node to keep the plant producing. Harvest in the early morning when stems are fully turgid. The productive cutting window extends for 60 days or more as plants continue to branch.

In the kitchen

Fresh feverfew leaves carry a strong, bitter, camphor-like flavour; a few leaves can be tucked into a sandwich or chopped finely into salad dressings in very small quantities. The flowers are edible and used as garnishes. The plant is best known as a traditional medicinal herb — leaves are consumed fresh or dried to prepare teas and tinctures. Lime-green and white flower varieties are prized as cut-flower filler in fresh and dried arrangements.

Storing

Fresh-cut stems last 7–10 days in clean water in a cool spot out of direct sunlight; recut stems at an angle daily. Dried stems can be hung upside down in small bundles in a dark, airy space and will retain their form for several months. Medicinal dried leaves should be stored in an airtight container away from light and heat, where they keep their potency for up to 12 months.