United States Department of Agriculture 

NATURAL RESOURCES CONSERVATION SERVICE 

Invasive Species Technical Note No. MT-18 

February 2008 

Ecology and Management of Common Tansy (Tanacetum vulgare L.) 

By 

Jim Jacobs, Invasive Species Specialist, NRCS, Bozeman, Montana 

Figure 1. A dense population of common tansy growing along a creek in Gallatin County, 

Montana.

Abstract 

Common tansy is a robust perennial forb that grows up to five feet (1.5 m) tall from large woody 

rhizomes. It produces large, aromatic, fern-like leaves and clusters of small button-like yellow 

flowerheads. It is a member of the sunflower family (Asteraceae) with origins in Eurasia and is 

normally found along roadsides and railroads, fields and pastures, ditch banks, riparian areas, 

and other moist places. Volatile oils produced in the leaves and flowers deter grazing by cows 

and horses. Historically, the oils have been used medicinally and the literature is fairly rich in 

common tansy’s pharmacological characteristics, but scant in its invasive ecology. Escaped 

cultivated plants brought to North America as early as the 1600’s are most likely the original 

sources of common tansy infestations. Populations often grow in thick clumps that crowd out 

grasses, forbs, and shrubs resulting in reduced livestock forage and wildlife habitat (see Figure 

1). It is listed as a Category 1 noxious weed in Montana and as a noxious weed in Wyoming. 

NRCS−Montana−Technical Note−Invasive Species−MT-18 1
Metsulfuron and clorsulfuron are the most effective herbicides for controlling common tansy 

when applied to actively growing plants before bloom at 0.5 oz./acre (Escort®, Cimarron®, or 

Telar®) or metsulfuron plus chlorsulfuron (0.5 oz. Cimmeron® X-tra). Tillage will control 

common tansy on cropland in rotation but follow-up tillage or herbicide applications 

(glyphosate: 2 qts./acre) may be needed to control plants regenerating from seeds or rhizomes. 

Tillage will also spread rhizomes. Persistent hand pulling and grubbing that removes the 

rhizomes will reduce small-scale populations. Mowing before bloom and repeated whenever 

plants initiate flowering will reduce seed production and over time may reduce populations 

where there are competitive grasses. One study suggests common tansy populations can be 

reduced using sheep or goat grazing, but animals should be removed four to six weeks before 

breeding to avoid reproductive problems. There are no biological control insects available for 

management of common tansy. Applying practices that encourage competitive desired plants 

such as forage harvest management, nutrient management, and prescribed grazing will improve 

control procedures and reduce the spread of common tansy. 

PLANT BIOLOGY 

Taxonomy 

Common tansy is in the sunflower taxonomic family (Asteraceae). The genus name, Tanacetum

was applied by Linnaeus in the eighteenth century and is believed to be derived from the Greek 

root athanotos which can be broken down to ‘without death’, implies immortality, and was likely 

a reference to the medicinal qualities and preservative uses of plants in this genus. The name 

Tanacetum can also be traced back to the Romans. Medieval Latin referred to common tansy as 

tanazetum or athanacetum, from which Old French changed it to tanesie (tanaisie in modern 

French) which sounds similar to tansy. The species name vulgare is from Latin and is often 

applied to weeds and usually used to mean ‘ordinary’ or ‘common’. Thus the common name is 

very closely related to the scientific name. Synonyms include Chrysanthemum vulgare and 

Tanacetum boreale. Another common name is golden buttons. 

There are about 50 annual or perennial, herbaceous or sub-shrub species in the Tanacetum genus 

mostly from the Old World. Current taxonomic classification lists seven Tanacetum species in 

the U.S. (USDA-NRCS Plants Database). Two species are native; T. bipinnatum (L.) SchultzBip. (Lake Huron tansy) and T. camphoratum Less. (camphor tansy). Lake Huron tansy grows 

in Michigan and Wisconsin where it is listed as threatened, in Maine where it is a species of 

special concern, and in Alaska, and Canada (also Siberia and Russia). Lake Huron tansy can be 

distinguished from common tansy by its low-growth habit (generally less than one foot or 10 to 

20 cm) and larger flowerheads (up to 3/4-inch or 2 cm). Camphor tansy is found in California, 

Oregon, and Washington, and while it is not listed as threatened, the habitat in which it grows is 

considered threatened. The leaves of camphor tansy are pinnately dissected, but the ultimate 

sections and teeth are rounded, giving the leaf a less jagged appearance than common tansy. 

Also, camphor tansy only grows up to two feet (60 cm) tall. There are four non-native 

Tanacetum species reported in the U.S. other than common tansy. Two can be found in Montana 

and Wyoming; T. balsamita (L.) commonly called costmary, and T. parthenium (L.) Schultz-Bip. 

(feverfew). The leaves of costmary are not finely-pinnately dissected, and the flowerheads of 

feverfew have white petal-like ray flowers. Neither species are considered invasive. Sexual 

hybrids between T. parthenium and T. vulgare have been documented. Common tansy is closely 

related taxonomically to oxeye daisy (Leucanthemum vulgare). 

NRCS−Montana−Technical Note−Invasive Species−MT-18 2
Figure 2. Common tansy leaf, flowering stem, and seed depiction (USDA-NRCS PLANTS 

Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, 

Canada and the British Possessions. Vol. 3: 522). 

Identification 

Common tansy is an erect herb that grows from two to five feet (0.6 to 1.5 m) tall. It has dark 

brown, stout, creeping rhizomes. Rhizomes of common tansy plants in Gallatin County 

measured 1/2 - 3/4 inch (5 to 19 mm) thick. Buds along the rhizomes can grow into shoots or 

roots. The roots are coarse, wiry, and have minimal development of fine roots or root hairs. The 

roots are shallow but extensive, and can occupy most of the upper two feet (60 cm) of the soil 

profile beneath a plant making common tansy competitive for soil moisture and nutrients. 

Basal and stem leaves are large, up to one foot long (30 cm) and six inches wide (15 cm), deeply 

pinnately dissected, the sections (pinnae) pinnately dissected again with deeply lobed or toothed 

segments (pinnules) so the leaf appears fern-like (see Figures 2 and 3). The central leaf vein 

(rachis) is winged with leaf tissue (see Figure 3). The leaves are hairless (glabrous, or nearly 

glabrous), glandular, dotted with minute depressions (punctate). Stems have numerous leaves 

(up to 20) arranged alternately from short petioles or sessile. When crushed, the leaves have a 

strong and distinctive menthol- or camphor-like smell from volatile oils. 

NRCS−Montana−Technical Note−Invasive Species−MT-18 3
Figure 3. A common tansy leaf showing the toothed pinnules on the deeply lobed 

pinnae along the winged rachis. 

The flowerheads are numerous (commonly 20 to 200) and arranged in a dense compound 

inflorescence that is somewhat flat-topped with the outer flowerheads developing before the 

inner flowerheads (corymb, see Figure 4). Individual flowerheads are made up of yellow disc 

flowers. There are no petal-like ray flowers. The flowerheads are about 1/4- to 3/8- inch (5 to 

10 mm) wide and often described as button-like. The bracts below the flowerheads are green 

with dry, thin, membranous, and translucent (scarious) margins and tips. The bracts overlap each 

other like shingles on a roof (imbricate). 

The individual flowers on the flowerhead are numerous (sometimes over 100) on a flat to low 

conic, naked (without bracts, bristles, or scales) receptacle. The flower has a short, five-lobed, 

yellow corolla tube with a short, crown-like pappus (often absent) at the base (see Figure 2, the 

pappus is absent in the illustration). The outer flowers on the flowerheads produce seeds and the 

inner flowers produce both pollen and seeds. The achene (seed) is very small (1.2 to 1.8 mm), 

five-ribbed with scattered sessile, transparent, non-mucilaginous glands on the outer surface 

(epicarp). 

NRCS−Montana−Technical Note−Invasive Species−MT-18 4
Figure 4. The “button-like” flowerheads of common tansy blooming in mid-August. 

Life history 

Common tansy is a short to long-lived perennial forb that reproduces vegetatively by rhizomes 

and sexually by seed. Aging by counting annual growth rings on rhizomes (herbchronology) 

from five populations in Gallatin County, showed the average age of rhizomes was 5.4 years 

(n=14, sd=2.5). Longevity varied depending on site. Dryer sites tended to support more longlived plants, up to ten years old. Live and dead rhizomes from a moist stream bank site showed 

rhizomes survived about three to four years. 

The seed biology of common tansy has not been studied, but the potential seed production is 

large. Stem densities in Montana averaged 100 stems/m2

 and each stem had one inflorescence at 

the apex. The inflorescence can have many flowerheads each with many flowers. In Gallatin 

County, Montana, a survey of five populations indicated the average number of flowerheads per 

inflorescence was 67 (n=12, sd=38.7). The mean number of flowers per flowerhead was 144 

(n=10, sd=44), and the estimated number of flowers per stem was 9,966 (n=10, sd=4,642). 

However, a large number of the achenes appeared unfilled. The estimated number of filled 

achenes per plant was 2,553 (n=10, sd=1978) and estimated achenes per square meter of area 

infested was 198,625 (n=10, sd=209,280). No information was found on the viability, 

germination, seedling growth, or rhizome development. However, about 75% of seeds collected 

in October germinated after one month of cold stratification indicating high viability and the 

ability to germinate upon seed set. The small size of the achene suggests that seedlings are small 

and not competitive. Common tansy most likely needs moist, disturbed soil for seedling 

establishment. 

Information on the timing of the vegetative and reproductive life history stages and their 

transitions is observational. Stem development from rhizome buds was observed in November, 

however, shoots usually emerge in spring after many perennial grass species have emerged. Leaf 

NRCS−Montana−Technical Note−Invasive Species−MT-18 5
expansion was observed in mid-May and by mid-June; plants can reach heights of three or more 

feet (1 m). Flower bud formation begins in June, the late-bud stage was observed in late-June, 

and plants bloom throughout most of August. Flowering, but not seed formation was observed 

in late October and early November along roadsides. Information on seed-set was not found. 

Flowers are reported to be pollinated by insects; however, common tansy has also been reported 

to deter pollinating insects in gardens. Stems and leaves die when soil moisture is depleted as 

early as August, but leaves will remain green through October and into November where 

moisture is available. Flowerheads remain intact and hold seeds through the fall unless 

mechanical action dislodges seeds from dried flowerheads. There are no obvious physical or 

morphological mechanisms of seed dispersal aside from the leverage action of tall, stiff, dried 

stems. 

Competitive Interactions 

A competition study conducted in Germany compared the biomass production and cover of bush 

grass (Calamagrostis epigejos), a tall rhizomatous grass, Canada goldenrod (Solidago 

canadensis), a tall rhizomatous forb, and common tansy. They were grown for five years in 

monocultures and mixtures on three soils representing a productivity gradient; top soil, “ruderal 

soil” (a mixture of top soil and subsoil), and sand. When growing in mixtures, average plant 

cover of common tansy was greater than either of the other species in all soil types in all years 

with a few exceptions. The exceptions were; the high productivity topsoil in the fifth year when 

slugs selectively defoliated the common tansy, and when growing in combination with Canada 

goldenrod in the mid-productivity ruderal soil in each of the five years. However, replacement 

diagrams suggest that common tansy and bush grass were equally competitive in sand and 

ruderal soil but bush grass was more competitive in the topsoil where common tansy was 

selectively defoliated by slugs. Similarly, slugs reduced common tansy’s ability to compete with 

goldenrod in the high productivity topsoil. However, on the ruderal soil, Canada goldenrod was 

more competitive than common tansy and the reverse was the case on the low productivity sand. 

There was evidence of niche separation between common tansy and the other species only on the 

ruderal soil, and when common tansy grew with Canada goldenrod on topsoil. 

The results suggest common tansy was a strong competitor on low productivity soils where it 

was better at acquiring nutrients than the other species. This could explain why common tansy 

populations grow in near-monocultures on sandy soils of riparian areas. On the high 

productivity experimental soil, common tansy was more productive than the other species, but 

was also susceptible to predation, presumably because of high nitrogen content in the leaves. 

This suggests selectively defoliating common tansy growing on productive soils will shift 

competition to favor rhizomatous grasses and forbs. On less productive soils, management 

targeting shoots and rhizomes may be needed to shift competition.

Habitat 

Native habitats of common tansy are sub-alpine mountain river valleys in Siberia. Most 

occurrences in Europe are associated with humans. This is also true of populations in North 

America. In Montana, common tansy was first reported in 1931 from a sawmill site on the 

Gallatin National Forest in Madison County. It has since been reported from gardens, along 

streams, rivers and lake shores, along roads and railroads, in swamps and marshes, irrigated 

pastures, moist valley bottoms, rangeland, dry hillsides, and vacant lots. It prefers open sites 

with moist soils for at least part of the growing season. All the common tansy populations 

surveyed in Gallatin County were growing with smooth brome (Bromus inermis). 

NRCS−Montana−Technical Note−Invasive Species−MT-18 6
Spread

Common tansy traveled from Europe to North America with the early settlers. It was 

recommended as a necessary plant for colonial herb gardens where it was reportedly cultivated in 

New England in 1638 and 1663. Escaping cultivation, it was considered naturalized throughout 

the northeast by 1785. It was reported from Iowa and Kansas by 1912, and was well 

documented in California by 1951. 

How common tansy escapes cultivation is not completely clear. Individual common tansy plants 

spread short distances by creeping rhizomes to form dense clumps. Seeds disperse by the 

mechanical action of dried stems flicking seeds from dried flowerheads. The small, light-weight 

seeds may also be carried long distances on water currents. It is doubtful seeds are blown long 

distances unless on the snow surface over winter. Seeds can be moved in the fur of animals, soil 

on animal hooves and paws, and on the clothes and footwear of people. Seeds can also be 

moved when inflorescences become attached to vehicles or equipment, and in mud on tires. It is 

possible that seeds are consumed by birds and spread via droppings. Rhizomes can be spread by 

tillage equipment, construction equipment, and in soil. Flowerheads baled in hay will disperse 

seeds when the hay is moved and fed to livestock. 

Impacts 

Common tansy infestations reduce livestock forage. The volatile oils in the leaves of common 

tansy deter grazing by cattle and horses during most of the growing season and plants are 

generally avoided. Elk have been observed to browse common tansy, but it is generally 

considered to reduce wildlife habitat. Dense clumps crowd out native plants and large 

infestations may reduce bio-diversity particularly in riparian areas. Common tansy infestations 

may reduce the habitat of pollinating insects. 

The essential oils from the leaves and flowers of common tansy have been the subject of a great 

deal of modern research. Extracts from European populations have identified 57 compounds 

divided into four groups; 1,8-cineole, trans-thujone, camphor, and myrtenol. There is variability 

in the amounts and ratios of the groups of oils produced depending on population, habitat, and 

time of year. 

The list of biological activities of 1,8-cineole (a monoterpene cyclic ether) is long and includes 

allelopathy, anesthetic, antibacterial, carcinogenic, fungicide, herbicide, insectifuge, nematicide, 

sedative, and testosterone hydroxylase inducer, to name a few. It is a toxin produced by leaves 

to defend against herbivory. Possums on a diet of cineole ceased feeding when bio-available 

blood levels saturated pre-systemic metabolism. This suggests ungulates have a certain tolerance 

for this chemical regulated by metabolism. Humans and rats metabolize cineole in the liver and 

excrete metabolites in the urine. 

Thujone is a monoterpene with a menthol-like aroma. In the nineteenth century, it was mixed in 

liquor (absinthe) and consumed by notable artists (and others), including Vincent Van Gogh, to 

increase brain activity, develop new ideas, expand imagination, cause hallucinations, and as an 

aphrodisiac. These effects have been proven mythic. It is a GABA receptor antagonist that 

allows neurons to fire more easily and cause spasms. Mice exposed to doses of 60 mg/kg 

experienced convulsions and death in one minute (Van Gogh reportedly experienced fits of 

convulsions). 

NRCS−Montana−Technical Note−Invasive Species−MT-18 7
Camphor is a terpene used in the manufacture of plastics, in lacquers and varnishes, in 

explosives and pyrotechnics, as a moth repellent, and as a preservative in pharmaceuticals and 

cosmetics. It relieves itching, pain, and creates the feeling of coolness when applied to the skin 

where it is readily absorbed. It is used as an antibacterial injection for infected root canals in 

dentistry. It is metabolized in the liver and eliminated in the urine. It is one of the active 

ingredients in Vicks VapoRub®. It is also used as a flavor enhancer in cooking, particularly in 

India. 

Myrtenol is an oxygenated monoterpene. Although it is not classified as an insect pheromone, it 

does attract pine bark beetles and has been used to enhance bait in insect traps. It has also been 

used as a beverage preservative, a flavoring, and as a fragrance.

MANAGEMENT

Herbicidal Control 1/

Common tansy can be managed using metsulfuron, chlorsulfuron, or metsulfuron plus 

chlorsulfuron. The herbicide labels indicate a rate of 1 to 2 oz./acre or 1 to 3 oz./acre using 

metsulfuron (Escort®) or chlorsulfuron (Telar®), respectively. However, herbicide trials 

showed metsulfuron applied at a broadcast rate of 0.5 oz. product (Escort® or Cimarron®) per 

acre at the late bud stage of development (late June) provided nearly 100% control of a 

population growing on moist soil one year after treatment. Similar results were found using 0.25 

oz. metsulfuron plus 0.25 oz. chlorsulfuron (similar to 0.5 oz./acre Cimarron® X-tra). A nonionic surfactant at 0.5% volume/volume or methylated seed oil (MSO) at 2% volume/volume in 

the spray solution is needed for these herbicides to be effective. Visible effects of the herbicides 

were not apparent until 45 days after treatment. These chemicals will also affect many shrub 

species. They can be applied to plants growing up to the edge of water, but cannot be applied 

directly to water or areas where surface water is present. Read herbicide labels for complete 

details of use restrictions. 

Where high water tables are not present, picloram (1 qt./acre Tordon® or Picloram 22K®) plus 

dicamba (1-2 qt./acre Clarity®) applied to actively growing plants in the bud to bloom stage can 

be used to control common tansy. However, reports indicate this treatment is less effective than 

the metsulfuron treatment and may be cost prohibitive. Picloram (2 qts. /acre) combined with 

dicamba (1 pt. /acre) applied to plants at bud stage provided 98% control of common tansy 24 

months after treatment. Where common tansy is growing in water, imazapyr applied at 1 qt./acre 

(Habitat®) will provide some control. Label restrictions should be carefully followed when 

applying herbicides to water. On cropland, glyphosate applied at 2 qts. product/acre to actively 

growing plants in combination with tillage may help control common tansy. 

NRCS−Montana−Technical Note−Invasive Species−MT-18 8
Table 1. Chemical and product name, recommended application rate, soil residual half life, and 

eco-toxicity of herbicides commonly used to control common tansy. The eco-toxicity is the lethal 

concentration of the herbicide when applied in a single dose kills 50 percent of the tested organism 

(the lower the number the more toxic the herbicide). Follow label guidelines for rangeland use and 

all other label requirements when applying herbicides to avoid damage to desirable plant species. 

Chemical name Product name Rate 

per Acre 

Half life 

(days) 

Eco-toxicity (LC50/EC50) 

Dicamba Clarity/Banvel 1 pt. 10 >100 mg/L 

Chlorsulfuron Telar 0.5 oz. 45 >150 mg/L 

Glyphosate many names 2 qts. 32 8.2 mg/L 

Metsulfuron Escort/Cimarron 0.5 oz. 14-180 >150 mg/L 

Picloram Tordon/Picloram 

22K 

1-2 qts. 90 10-100 mg/L 

1/

Any mention of products in this publication does not constitute a recommendation by the NRCS. It is a 

 violation of Federal law to use herbicides in a manner inconsistent with their labeling. 

Hand Pulling

Hand pulling, digging, grubbing, and hoeing may be practical on small populations of common 

tansy and if applied persistently can reduce populations. Pulling and grubbing should remove 

the rhizome to be effective. Follow-up treatments will be necessary where a persistent rhizomes 

and seed banks exists. Seeding soil disturbances with competitive plants may help reduce reestablishment of common tansy. 

 

Mowing 

Mowing, if applied before bloom, will reduce flowering and seed production. It is recommended 

to mow to a four-inch or greater stubble height to maintain the vigor of native and desirable plant 

species which may replace common tansy over time with repeated mowing. Mowing after 

flowering when seeds have set may increase the spread of common tansy seeds. Mowing can be 

used to reduce litter cover before herbicide application and thereby increase herbicide contact 

with foliage when applied to re-growth. 

Tilling

Common tansy is not normally a problem in cultivated crop fields because it is controlled by 

tillage procedures that clean crop fields of weeds. However, because the rhizome has 

regenerative buds, it is possible to spread common tansy within a crop field and between fields. 

Seeds are also believed to be spread with the movement of soil. Repeated tillage or an 

application of glyphosate to common tansy plants that regenerate from rhizomes or seeds 

following tillage will reduce common tansy spread on tilled fields. Cleaning tillage equipment 

of soil that may contain seeds or rhizomes is recommended after use on fields where common 

tansy has been growing and before use on weed-free fields. 

Prescribed Burning 

There is no indication that prescribed burning by itself will control common tansy, 

predominantly because it can regenerate from rhizomes not affected by heat. However, dense 

NRCS−Montana−Technical Note−Invasive Species−MT-18 9
patches of common tansy with dried litter buildup can burn hot and fast and pose a potential 

wildfire danger. Therefore, prescribed burning can be used to control undesirable dead 

vegetation buildup and reduce wildfire hazards. Prescribed burning can also be used to prepare 

sites for herbicide application by removing dead plant litter blocking herbicide coverage on 

actively growing vegetation. Prescribed burning should be integrated with other practices such 

as herbicide management, grazing management, and planting riparian herbaceous cover. 

Grazing Control 

Common tansy is reported to be toxic to livestock and abortions in cattle were reported from the 

mid-west United States. However, in Montana most classes of livestock and some wildlife have 

been observed to eat common tansy with no known adverse effects. The potentially toxic 

volatile oils produced by the leaves and inflorescences of common tansy can be metabolized by 

mammals and the metabolites excreted in the urine. Research indicates that herbivores have a 

toxin blood-level feedback mechanism for some of the oils produced by common tansy that, 

when threshold levels are reached, deters further grazing. This natural feedback mechanism may 

be sufficient to prevent poisoning as long as alternative forages are available to the herbivores. 

Sheep have been used to manage common tansy in Montana. Clipping data from grazing 

enclosures paired with grazed plots suggest sheep consumed up to 90% of the aboveground biomass of common tansy while consuming a slightly greater or lesser quantity of perennial grass 

bio-mass depending on the availability of each forage class (where more common tansy than 

grass was available, more common tansy relative to grass was consumed). Long-term impacts of 

repeated sheep grazing on common tansy population size and plant community dynamics are not 

known, but observations suggest common tansy populations may be decreased and grass 

populations increased with consecutive years of season-long sheep grazing (see Figure 5). While 

no toxic effects of eating common tansy were reported from the flock used in the study, it is 

recommended to remove sheep from common tansy infestations four weeks prior to breeding to 

avoid reproductive problems. Similar grazing recommendations most likely apply to goats. 

a. b.

b. 

Figure 5. Photos of a common tansy population in western Montana grazed by sheep for two 

years; a. the plant community in 25 June 2004 before sheep grazing started and b. the plant 

community in 15 May 2007 after three seasons of grazing. The difference in season between 

photos does not provide an accurate comparison considering grasses may initiate growth in the 

spring before common tansy. However, it appears that grasses are increasing where sheep have 

grazed. 

NRCS−Montana−Technical Note−Invasive Species−MT-18 10
Cultural Control 

Plant competition reduces the invasiveness of common tansy and increases the effectiveness of 

control applications. Therefore, practices that increase the competitiveness of desirable plant 

species such as conservation crop rotation, nutrient management, irrigation water management, 

forage harvest management, critical area planting, and prescribed grazing will make the 

environment less hospitable for common tansy to survive and spread. 

Biological Control 

Currently, no biological control agents are available for management of common tansy. There 

are numerous insects and diseases that attack common tansy in its native range and several 

biological control insects have been identified: Isophrictis striatella is a moth that mines the 

flowerhead, stem, and rhizome; Microplonus millefolii is a stem-mining weevil; moths in the 

Dichrorampha genus feed on rhizomes; Cassida stigmatica beetles feed on leaves; and the gall 

midge Rhopalomyia tanaceticola attacks the rosette, stem, and flowerhead. A joint United States 

and Canadian consortium is currently funding a program of insect biological control of common 

tansy. 

Re-vegetation 

Species selected for re-vegetating disturbed sites and common tansy infestations should be 

appropriate for management objectives, adapted to site conditions, and competitive with the 

weed. Management objectives will determine if introduced or native species are seeded and the 

combination of species in the seed mix. The environmental conditions of the site including 

precipitation, soil texture and depth, slope and aspect, will affect species establishment. Refer to 

Montana Plant Materials Technical Note 46, ‘Seeding Rates and Recommended Cultivars,’ and 

Extension Bulletin EB19 ‘Dryland Pasture Species for Montana and Wyoming’ for seeding rate 

guidance and re-vegetation species selection. State, Area, and Field Resource Specialists can 

help determine the most appropriate, site-specific species mix and timing of seeding. 

In most cases, herbicidal suppression of common tansy is needed for re-vegetation of infested 

areas. The herbicides listed in Table 1 will control common tansy and reduce competition during 

the establishment period with little or no injury to emerging grass seedlings. This is especially 

important for species that are slow to establish like many of the native grasses. However, where 

herbicides have been applied, chemical carryover should be assessed prior to planting permanent 

vegetation particularly where shrubs and forbs are being used. Common tansy is often found in 

all the hydrologic zones of stream banks and riparian areas. Conservation practices that address 

riparian restoration, such as Channel Bank Vegetation (Code 322), may be needed after common 

tansy control to maintain hydrologic cycles and prevent soil and water resource concerns such as 

erosion and sedimentation. 

Integrated Pest Management 

Integrated pest management is the application of two or more management alternatives that are 

complimentary in weed suppression, reduce the environmental risks of pesticides, increase the 

longevity of control procedures, and improve crop production, or conservation of resources. The 

integration of multiple management practices should be designed based on the stage of common 

tansy invasion. On small populations in the early phase of invasion, aggressive herbicidal 

NRCS−Montana−Technical Note−Invasive Species−MT-18 11
NRCS−Montana−Technical Note−Invasive Species−MT-18 12

control should be combined with cultural practices that strengthen the competitiveness of the 

plant community, such as prescribed grazing and forage harvest management. In areas with 

large scale infestations in the later phases of invasion, first priority should be given to herbicide 

application to eradicate small satellite populations and to reduce spread along the invasion front 

of the parent population. Second priority should be given to reducing the parent population 

using herbicide management, grazing with sheep or goats, and re-vegetation with competitive 

plants where needed. On dense populations of common tansy, prescribed burning, mowing, or 

intensive grazing will reduce plant litter and may improve herbicidal control by increasing 

chemical contact on actively growing leaves. On grazing lands, prescribed grazing management 

should be timed to maintain the vigor of rangeland plants and prevent common tansy seed 

spread. On crop and hay land in rotation, tillage combined with herbicide treatment will be more 

effective than either treatment applied alone. On disturbed sites, pastures, and rangeland where 

competitive plants have been lost, re-vegetation following common tansy control will improve 

the longevity of the control application. Monitoring before and after management will allow 

evaluation of management effectiveness and locate regenerating populations. 

References 

Judzentiene, A. and D. Mockute. 2005. The inflorescence and leaf essential oils of Tanacetum 

vulgare L. var. vulgare growing wild in Lithuania. Biochemical Systematics and Ecology 

33:487-498. 

LeCain, R. and R. Sheley. 2006. Common tansy (Tanacetum vulgare). Montana State 

University Extension MontGuide MT 199911 AG. 4 p. 

Mitch, Larry W. 1992. Intriguing world of weeds – tansy. Weed Technology 6:242-244. 

Rebele, F. 2000. Competition and coexistence of rhizomatous perennial plants along a nutrient 

gradient. Plant Ecology 147: 77-94.