🌿 Tansy

Tanacetum vulgare

herbs perennial herb

☀️ Sun

full sun to partial shade

💧 Water

low (drought-tolerant, dislikes wet soil)

🗺️ Zones

3–8

🪴 Soil Type

well-drained loam; tolerates poor, dry, or disturbed soil

🧪 Soil pH

5.5–7.5

💧 Drainage

well-drained to dry

📏 Spacing

24–36 inches

📐 Height

36–60 inches

📅 Days to Maturity

365 days (perennial, flowers second year from seed)

🍴 Edible Parts

🍽️ young leaves (very sparingly🍽️ historically used as flavoring; TOXIC in quantity)🍽️ flowers (historically in small amounts)

🤝 Companions (7)

🤝 Raspberry

Tansy deters raspberry cane borers and Japanese beetles; planted at cane row ends it repels flying insect pests.

🤝 Potato

Tansy attracts beneficial insects including parasitic wasps, ladybugs, and lacewings that prey on potato pests; its strong scent may confuse some pest insects. Note: Specific CPB deterrence lacks strong scientific evidence per extension research.

🤝 Apple

Tansy planted beneath apple trees repels codling moths and apple maggot flies; also deters ants that farm aphids on apple leaves.

🤝 Rose

Tansy deters Japanese beetles, aphids, and rose chafers from roses; yellow button flowers contrast beautifully with roses.

🤝 Cucumber

Tansy repels cucumber beetles and squash bugs; tall tansy provides light shade that prevents cucumber scald.

🤝 Grape

Tansy deters Japanese beetles that skeletonize grape leaves; accumulates potassium beneficial for grape fruit quality.

🤝 Peach

Tansy deters peach tree borers and oriental fruit moths; aromatic leaves mask peach scent from flying pests.

⚠️ Keep Apart (4)

⚠️ Lettuce

Tansy's aggressive rhizomatous roots compete with lettuce's shallow root system; tansy's allelopathic compounds inhibit lettuce seed germination.

⚠️ Bean

Tansy can inhibit legume growth through allelopathy; its dense root mat competes with bean surface roots.

⚠️ Pea

Tansy's tall growth shades out low-growing peas; allelopathic root exudates inhibit pea nodulation and nitrogen fixation.

⚠️ Strawberry

Tansy's spreading roots invade strawberry beds, competing for space; its shade reduces strawberry fruit production.

💊 Medicinal Uses

Anthelmintic (expels worms), insecticidal, emmenagogue. Contains thujone (neurotoxic in high doses — same compound as wormwood). Historically used as vermifuge for intestinal parasites and to induce menstruation. MODERN WARNING: Internal use is discouraged due to thujone toxicity — can cause convulsions, liver damage, and miscarriage. External use only: insect repellent, rinse for scabies and lice. Essential oil is highly toxic — do not ingest.

📜 History & Traditional Uses

Ancient Greeks used tansy for preserving bodies before burial. Medieval Europeans used it as strewing herb (antiseptic floor covering), insect repellent, and aromatic. Traditional 'tansy cakes' eaten at Easter to 'purify the blood' after Lent's fish diet. Used in embalming in some cultures. Placed in coffins and wrapped around corpses to repel worms. Colonial Americans used it to preserve meat and repel ants. Listed in early pharmacopeias as a vermifuge.

📝 Notes

Powerful insecticidal properties — leaves repel ants, flies, moths, fleas, mosquitoes, and cockroaches. Dried tansy in sachets repels clothes moths traditionally. Accumulates potassium from soil. Rhizomatous spreader — plant where it can be contained or use root barrier. Attractive fern-like foliage and bright yellow button flowers. Rub fresh leaves on skin as natural insect repellent. Do not plant near livestock pastures — toxic to cattle and horses. 'Isla Gold' is a less-invasive variegated cultivar.