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Tanacetum vulgare is often confused with:
Achillea millefolium Achillea millefolium
Native alternative(s) for Tanacetum vulgare:
Rudbeckia hirta Composite head detail
Plants that fill a similar niche:
Achillea millefolium Achillea millefolium
Melia azedarach close up of flowers
Heracleum maximum Form in native habitat

Cow Bitter Tanacetum vulgare

Previously known as:

  • Chrysanthemum vulgare
  • Pyrethrum vulgare
Phonetic Spelling
tan-ah-SAY-tum vul-GAR-ay
This plant has high severity poison characteristics.
See below
This plant is an invasive species in North Carolina
Description

Common Tansy is an aromatic herbaceous perennial that has fern-like foliage and yellow button-like flowers. The plant grows erect and averages 1-5 feet tall. It spreads rapidly by its rhizomatous root system and prolific seed production. The plant has been listed as a noxious weed in many areas of the United States. Common Tansy is a member of the Asteraceae or Aster family. Other common names include Golden Buttons, Tansy, Bitter Buttons, Cow Bitter, and Garden Tansy.

The plant is a native of Europe and Asia. Common Tansy was brought to North America by early settlers in the 1600s for medical and horticultural purposes. It was used for the treatment of constipation, hysteria, intestinal worms, rheumatism, and digestive disorders. The leaves were used to wrap corpses to prevent rapid decay. They were also used to protect meats from flies and ants. More recently, Common Tansy has been researched for use as an insecticide or mosquito repellent. The plant has naturalized in the northern United States and southern Canada. It is found along roadsides, railroads, pastures, streams, and ditches.

The genus name, Tanacetum, is derived from the Greek word, "Athanasia," which means"immortal." The species name, vulgare, is Latin and means "common."

Common Tansy prefers full sun to partial shade. It grows in well-drained soils. It tolerates a variety of soils including dry and poor soils, but it actually prefers moist humus soils. Common Tansy is problematic since it forms a dense cover, completes with native plants, and degrades pasture land. The plant reproduces by seeds, rhizomes, and root fragments. It is important to deadhead or shear off blooms to control self-seeding. Hand pulling and mowing may also help to reduce seed production if properly timed. Common Tansy can be controlled with common herbicides. The best defense is to provide better land management and developing a long-term ecological strategy.

Common Tansy contains an oil known as thujone, which may cause skin irritation or contact dermatitis. When handling this plant, it is important to wear gloves and long sleeve shirts to avoid exposure.

Thujone is a potent chemical, and excess consumption may cause convulsions or death. Common Tansy can be toxic to horses, cows, and humans especially if eaten or used in excess. However, sheep and goats can tolerate the plant and have been used to control the weed.

The leaves are feathery, fern-like, and have a pungent camphor-like odor when crushed. The flowers are clusters of golden yellow buttons that bloom from July to September. The fruits are tiny dark brown seedheads that mature in late summer to fall.

When considering Common Tansy in your garden, it is important to be aware that the plant is an invasive noxious weed, and it is prohibited or restricted in some areas across the United States. It is prohibited in Colorado, Minnesota, Montana, Wyoming, and parts of Washington State. If planted, it is important to clip off the spent flowers to control self-seeding. It is not recommended for flower beds or borders due to its spreading rhizomes.

Quick ID Hints:

  • Green feathery, fern-like leaves
  • The leaves have a strong pungent odor when crushed
  • The flowers are golden yellow button-like blossoms
  • The stems are reddish-brown in color

Insects, Diseases, and Other Plant Problems:  Common Tansy has no serious pests or disease problems. Spider mites can be a problem in some areas. The plant can be very aggressive when in the optimum environment.

See this plant in the following landscape:
Herb & Flower Cottage Garden
Cultivars / Varieties:
  • 'Isla Gold'
    Lacey golden foliage, deer resistant
'Isla Gold'
Tags:
#invasive#poisonous#full sun tolerant#weeds#yellow flowers#weedy#herb garden#summer flowers#Noxious Weed List#disturbed areas#fern-like#malodorous#problem for horses#contact dermatitis#toxic to humans#problem for cattle
 
Cultivars / Varieties:
  • 'Isla Gold'
    Lacey golden foliage, deer resistant
'Isla Gold'
Tags:
#invasive#poisonous#full sun tolerant#weeds#yellow flowers#weedy#herb garden#summer flowers#Noxious Weed List#disturbed areas#fern-like#malodorous#problem for horses#contact dermatitis#toxic to humans#problem for cattle
  • Attributes:
    Genus:
    Tanacetum
    Species:
    vulgare
    Family:
    Asteraceae
    Uses (Ethnobotany):
    The Pilgrims were the first to bring Common Tansy seeds to North America. The plant was to be used for medicinal purposes such as treating ulcers, constipation, hysteria, intestinal worms, rheumatism, jaundice, and gastrointestinal problems. From the 17th to 19th century, Europeans and Americans wrapped corpses in Common Tansy to prevent rapid decay. The leaves were used to repel flies, ants, and fleas around meats. The plant has also been researched as a possible insect repellant or insecticide for mosquitoes.
    Life Cycle:
    Perennial
    Recommended Propagation Strategy:
    Division
    Seed
    Country Or Region Of Origin:
    Native to Europe and Asia
    Distribution:
    Native: Albania, Austria, Baltic States, Belarus, Belgium, Bulgaria, Czechoslovakia, Denmark, Finland, France, Germany, Great Britain, Greece, Hungary, Inner Mongolia, Italy, Japan, Korea, Manchuria, Mongolia, Netherlands, Norway, Poland, Portugal, Romania, Russia, Spain, Switzerland, Turkey, Ukraine, West Siberia, Xinjiang, and Yugoslavia; Introduced: Australia, Bolivia, Brazil, Canada: Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan, and Victoria; Ecuador, Iceland, New South Wales, Panama, Paraguay, Peru, Tasmania, US: AL, AR, AK, CA CO, CT, GA, IL, IN, IA, KS, KY, LA, ME, MD, MA, MI, MN, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SD, TN, UT, VT, VA, WA, WV, WS, and WY; and Venezuela
    Fire Risk Rating:
    high flammability
    Play Value:
    Fragrance
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Deer resistant. Drought tolerant.
    Dimensions:
    Height: 1 ft. 0 in. - 5 ft. 0 in.
    Width: 0 ft. 9 in. - 1 ft. 6 in.
  • Whole Plant Traits:
    Plant Type:
    Herbaceous Perennial
    Poisonous
    Weed
    Habit/Form:
    Clumping
    Erect
    Growth Rate:
    Rapid
    Maintenance:
    Low
    Texture:
    Fine
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    High Organic Matter
    Soil pH:
    Acid (<6.0)
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Available Space To Plant:
    12 inches-3 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    3a, 3b, 4b, 4a, 5b, 5a, 6b, 6a, 7a, 7b, 8b, 8a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Display/Harvest Time:
    Fall
    Fruit Type:
    Achene
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    The fruits are 5 brownish angled achenes. One plant is capable of producing 50,000 seeds per year.
  • Flowers:
    Flower Color:
    Gold/Yellow
    Flower Inflorescence:
    Corymb
    Flower Value To Gardener:
    Showy
    Flower Bloom Time:
    Fall
    Summer
    Flower Shape:
    Radial
    Flower Size:
    < 1 inch
    Flower Description:
    The flowers are golden yellow button-like blooms that appear in clusters of 20-200 flowerheads. Each flower measures from 1/4 to 1/2 inch wide. They are similar to the tiny disc flowers of a daisy but have no flower petals. The flower clusters can measure up to 4 inches wide. They typically bloom from July to September.
  • Leaves:
    Leaf Color:
    Green
    Leaf Feel:
    Soft
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Arrangement:
    Alternate
    Leaf Margin:
    Dentate
    Lobed
    Hairs Present:
    No
    Leaf Length:
    > 6 inches
    Leaf Width:
    3-6 inches
    Leaf Description:
    The leaves are green and have a camphor-like odor when crushed. They are arranged alternately. There are basal and cauline leaves. The leaf blades are oblong or elliptic in shape and pinnately lobed. The leaf is deeply divided into narrow segments. The margins are dentate, and the surface is glabrous to sparsely hairy. The leaves measure from 2 to 6 inches, and up to 12 inches long, and 4 inches wide.
  • Stem:
    Stem Color:
    Brown/Copper
    Red/Burgundy
    Stem Is Aromatic:
    No
    Stem Form:
    Straight
    Stem Surface:
    Smooth (glabrous)
    Stem Description:
    The stem is erect, branched, and glabrous to sparsely hairy. The stem color is brown to reddish-brown.
  • Landscape:
    Landscape Location:
    Naturalized Area
    Landscape Theme:
    Cottage Garden
    Design Feature:
    Border
    Mass Planting
    Resistance To Challenges:
    Deer
    Drought
    Erosion
    Problems:
    Contact Dermatitis
    Invasive Species
    Poisonous to Humans
    Problem for Horses
    Weedy
  • Poisonous to Humans:
    Poison Severity:
    High
    Poison Symptoms:
    Dried leaves have been used to make teas, but the current uses of this plant in teas, food, and medicine are almost non-existent. Thujone can be fatal in large quantities.
    Poison Toxic Principle:
    Thujone
    Causes Contact Dermatitis:
    Yes
    Poison Part:
    Leaves