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Tansy Flower Guide: A Bold, Bug-Repelling Beauty for Your Garden

Tansy Flower on Pixabay
Botanical Name
Tanacetum vulgare
Plant Type
Flowers
Perennial Flowers
Sun Exposure
Full Sun
Part Sun
Soil pH
Varies
Bloom Time
Summer
Fall
Flower Color
Yellow
Hardiness Zone
3
4
5
6
7
8
Special Features
Attracts Bees

Learn how to grow, care for, and control this cheerful yellow herb that repels pests—and why it’s both helpful and a little wild in the garden.

Samantha Johnson
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Discover tansy, a tough-as-nails herb that bugs off pests and rolls out the welcome mat for pollinators. With golden button blooms and feathery green foliage, tansy adds old-world charm to veggie patches, borders, and cottage gardens alike. In this guide, we’ll dig into everything you need to know about growing tansy—how to plant it, care for it, and use its garden superpowers to your advantage.

Bonus? Deer tend to steer clear. Thanks to its strong scent and bitter taste, tansy is considered deer-resistant—a handy trait for gardens in browsing zones.

About Tansy

Tansy (Tanacetum vulgare)—also known as golden buttons, garden tansy, and bitter buttons—is a perennial herb in the daisy family (Asteraceae), related to asters, sunflowers, and chrysanthemums. It typically grows 1 to 5 feet tall and blooms from midsummer to early fall with clusters of fragrant, button-like yellow flowers. The upright stems are lined with fern-like, aromatic leaves that give tansy its distinctive look.

A historic favorite, tansy was likely brought to North America by the Pilgrims in 1620. Over the centuries, it’s been used in teas, old-time remedies, and even meat preservation. These days, it’s mostly grown for its ornamental value—and its pest-fighting reputation.

Is Tansy Invasive?

Before planting, it’s important to know that tansy can be invasive. It spreads aggressively by seed and underground rhizomes, and even small root fragments can regrow into new plants. 

Because of this, tansy is listed as a noxious or prohibited weed in parts of the Pacific Northwest, Midwest, and Northeast. Be sure to check your local regulations before planting.

That said, gardeners who want to grow tansy can take precautions to keep it well-mannered:

  • Plant in containers or raised beds to contain the roots.
  • Deadhead flowers before they go to seed.
  • Monitor spreading rhizomes and remove any wandering shoots.

Prefer to Play It Safe?

If you love the look or function of tansy but want to avoid its invasive habits, try these better-behaved alternatives:

  • Yarrow (Achillea millefolium) – A native wildflower that’s hardy, pollinator-friendly, and ferny in texture.
  • Golden Marguerite (Anthemis tinctoria) – Similar yellow blooms, with a more controlled growth habit.
  • Fennel (Foeniculum vulgare) – Feathery foliage, tall structure, and useful in the kitchen.

Is Tansy Poisonous?

Yes—tansy contains toxic compounds that can be harmful to humans, pets, and grazing animals. While historically used in medicine, it’s not considered safe to ingest today. Avoid planting near children’s play areas or where livestock or pets roam. Like many herbs, tansy is best enjoyed for its looks and fragrance—not for snacking.

Why Gardeners Still Grow It: Tansy’s Pest-Repelling Powers

Despite its downsides, tansy remains popular with organic gardeners for one big reason: it’s a natural pest deterrent. The plant’s essential oils are rich in compounds like thujone, camphor, and 1,8-cineole, which have shown insect-repellent properties in lab studies.

Here are a few notable examples:

  • Colorado Potato Beetle (Leptinotarsa decemlineata): Tansy essential oil has been shown to significantly deter feeding behavior in these beetles. Treated leaves were less likely to be eaten, suggesting potential as a natural pesticide. Source: PubMed, 2020
  • Green Peach Aphid (Myzus persicae): Allelochemicals from tansy have strong repellent effects against this aphid species, making it a useful companion for aphid-prone plants. Source: ScienceDirect
  • Fall Armyworm (Spodoptera frugiperda): When 2% tansy oil was added to artificial diets in lab tests, 73% of larvae died within 48 hours—pointing to its potential as a natural insecticide. Source: USDA CRIS Database

While more research is needed in field settings, these results suggest tansy may help protect nearby crops—especially potatoes, brassicas, and tomatoes—when used as a companion plant.

Today, tansy is primarily grown as a companion plant to deter pests from nearby crops and add a touch of historic flair to modern gardens. Its essential oils are rich in compounds like thujone, camphor, and 1,8-cineole, which have demonstrated insect-repellent properties in scientific studies. 

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Planting

Before planting, check if tansy (Tanacetum vulgare) is considered invasive or restricted in your state. If it’s allowed, you’ll discover it’s a hardy, low-maintenance perennial that’s easy to grow.

Tansy’s easygoing—just give it some sun (6+ hours is best) and decent drainage. It can handle dry spells and crummy soil, though it’s happiest in loamy ground.

When to Plant

  • Seeds: Sow directly outdoors after the last frost date in spring.
  • Divisions: If dividing mature plants, fall is the best time to replant the sections.

How to Plant

Like many hardy perennials from temperate climates, tansy seeds may benefit from cold stratification—a simple process of storing seeds in the fridge for 2 to 4 weeks to mimic winter conditions and encourage germination.

Before planting, consider how you want tansy to work in your garden. Some gardeners use it as a natural perimeter plant to help deter mosquitoes, flies, and even small mammals like mice.

  • Sowing Depth: Tansy seeds are tiny, so plant them shallowly—just â…›- to ÂĽ-inch deep. A light dusting of soil is all they need.
  • Spacing: Sow seeds about 12 inches apart, or sow densely and thin the seedlings as they emerge.
  • Watering: Keep the soil moist (but not soggy) until seedlings are established. Once grown, tansy is quite drought tolerant.

Growing

Tansy spreads through below-surface rhizomes and also by seed.

  • Tansy is primarily a full-sun flower, but it can tolerate some shade, giving you more flexibility in placement.
  • Tansy is tough, and fairly drought resistant when mature, so you definitely don’t want to overwater.
  • Fertile, well-draining soil is a great start, but soil type really can vary as tansy isn’t picky (which is part of why it can be invasive at times!).
  • It’s hardy in Zones 3 to 8, but because it requires cold stratification, it may struggle to propagate in warmer regions.
  • Honey bees love tansy, so growing it can bring in the pollinators while discouraging “bad” bugs.
  • As with so many “wildflowers,” tansy is quite self-sufficient and probably won’t need fertilizing or soil amendments.
  • To prevent tansy from spreading where you don’t want it, plan on controlling the area around your tansy by mowing or a similar method.
  • Soil pH isn’t terribly important; tansy can handle a range from approximately 5.0 to 7.5.
  • The fern-like leaves of tansy add interest and texture to the garden.
  • To help keep spreading under control, plan on removing flowers before they go to seed.
  • Tansy dries beautifully and makes a great flower for this purpose.
  • It also makes an excellent companion plant, helping to act as a natural insect repellent to protect plants nearby.
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Pests/Diseases

Because of its natural hardiness and bug-repelling nature, Tansy has few foes in the world. Aphids may try to forge an offense, but it’s usually not a real problem and they can often be dispatched with a hose. But speaking of hoses—too much moisture is probably your tansy’s biggest threat. It can lead to fungal issues on and around the plant and disrupt its preference for dry soil.

Wit and Wisdom

  • In ancient Greek mythology, the shepherd Ganymede used tansy as a magic potion to live forever. According to the North Carolina State Extension, the Greek word athanasia means “immortal” and is related to the name of the plant.
  • In past times, tansy was used as a bit of a good-luck charm, even placed above barn doorways in a manner somewhat similar to a horseshoe. Of course, tansy’s fly-repellent properties may have been the real reason!
  • Exodus 12:8 in the Bible mentions meal preparation: “…with bitter herbs they shall eat it.” The “bitter herbs” could easily have contained tansy among others.
  • While tansy isn’t recommended for human use today because of its high toxicity, in centuries past it was utilized in various folk remedies as a deworming agent.
  • Some say the Pilgrims brought tansy to the New World.
  • Tansy is native to Europe and Asia, but has naturalized, so you’ll find it across North America in ditches, along roadsides and pastures.
Flowering tansy plant growing wild in pastures.
You’ll often find tansy patches in pastures and fields and along roadsides and ditches. Credit: Arcaion
Flowers
About The Author

Samantha Johnson

Samantha Johnson is an award-winning author and gardening expert with over 20 years of experience cultivating heirloom vegetables and sharing her passion for rural living. Read More from Samantha Johnson
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Comments

Connie (not verified)

2 weeks 1 day ago

Agreed. There’s an area in northern Saskatchewan that is COVERED with this invasive weed. Please don’t plant!!!

W Jenkins (not verified)

2 weeks 3 days ago

This author must not live in Pacific NW where tansy is incredibly invasive and a horrible bane of rural and small communities. It is a weed that has been combated for decades. Almost a century ago the cinnabar caterpillar was introduced in the Pac NW as a biological controller, with limited success.
A little research goes a long ways in educating a person on the staggering costs some countries and regions spend in trying to control this invasive, toxic plant.

Lucy (not verified)

2 weeks 3 days ago

Be very careful planting Tansy near pastures where it could spread. Tansy is fatal to horses when consumed in enough quantity and horses will eat it without regard.