Fernleaf Yarrow

Fernleaf Yarrow (Achillea filipendulina)

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Management Category

Synonyms

Soldier’s Woundwort
Nosebleed
Milfoil
Achillea eupatorium
Achillea filicifolia
Tanacetum angulatum

ID Characteristics

General: Fernleaf Yarrow is a flowering herbaceous plant in the Asteraceae (daisy) family.

Flowers: Are yellow and long-lasting. These large flower clusters are comprised of tiny rays and discs and can measure up to 10 cm across.

Stems: Are erect, rising above the foliage to 90 – 150 cm tall.

Leaves: Fern-like, aromatic (spicy) when crushed, and green. Fernleaf Yarrow leaves are generally 5 – 20 cm long, divided into as many as 15 pairs of thin, toothed segments, giving the plant a feathery or fern-like look (hence its name). Fernleaf Yarrow leaves grow fairly evenly in a spiral pattern along the stem. The leaves have a bitter taste.

Roots: Are shallow but fibrous and abundant, and they easily spread horizontally through the soil.

Similar Species

Non-Native:

Thayne Tuason, CC BY-SA 4.0 via Wikimedia Commons

Common Yarrow (Achillea millefolium) looks similar to Fernleaf Yarrow, but the latter is taller.

Habitat and Origin

Fernleaf Yarrow is native to the Caucasus and Central Asia.

Fernleaf Yarrow is commonly found flourishing in waste areas, meadows, pastures as well as alongside railway tracks and roads. It thrives in full sun and can subsist in a variety of soil conditions, but prefers dry soil.

How It Spreads

Fernleaf Yarrow reproduces both by seed and vegetatively, through underground rhizomes.

Fernleaf Yarrow seeds are spread by humans and animals; root cuttings or fragments are also responsible for the plant’s vegetative spread. Lastly, since Fernleaf Yarrow is still sold in the horticultural trade, it is sometimes found in wildflower seed packs, sold in nurseries and planted by gardeners.

Impacts

Health:

Toxic to dogs, cats and horses.

Ecological:

Outcompetes native plants
Reduces biodiversity

Economic:

Fernleaf Yarrow hosts powdery mildew, rust and stem rot, which can spread to farmers’ crops.

Stop the Spread

Fernleaf Yarrow is widespread in the Sea to Sky region, and site-scale control options are either ineffective or futile. While Fernleaf Yarrow is not included in SSISC’s control programs, we recommend avoiding its cultivation.

Learn to identify Fernleaf Yarrow: use the images presented in this profile page to learn how to identify Fernleaf Yarrow

What to do if you spot it: You can report any Fernleaf Yarrow sighting by visiting our reporting page.

DO:

Regularly monitor properties for weed infestations.
Ensure soil and gravel are uncontaminated before transport.
Minimize soil disturbances (e.g., use grazing plans that prevent soil exposure from overgrazing) and promptly revegetate disturbed areas to prevent the growth of Fernleaf Yarrow. Use seed mixes with dense, early colonization (e.g., alfalfa or barley) to revegetate exposed soil and resist invasion.
Check wildflower mixes to ensure that they do not contain Fernleaf Yarrow.
Ensure all flowering heads or buds are bagged or covered to prevent spread during transport to designated disposal sites.
Maintain a healthy, thriving native plant community to help prevent the spread of Fernleaf Yarrow to some extent.

DO NOT:

Unload, park or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.
Plant Fernleaf Yarrow in a garden, no matter how well-contained its enclosure may seem.
Compost any flowering heads or buds. Instead, dispose of Fernleaf Yarrow in the general/household waste stream at the landfill as the seeds will be able to persist the composting process.
Move soil, gravel, or fill that has been contaminated with Fernleaf Yarrow.

Control

Mechanical

Digging and hoeing areas where Fernleaf Yarrow has spread may help slo the plant’s spread, but mechanical control is only truly effective if it goes down at least 30 cm into the soil and removes all Fernleaf Yarrow plant material (since the rhizomes can generate new plants).

Chemical

Dicamba, chlorsulfuron, clopyralid, MCPA, tricloplyr and 2,4-D are all reported to be effective in controlling Fernleaf Yarrow infestations.

We recommend that any herbicide application is carried out by a person holding a valid BC Pesticide Applicator Certificate. Before selecting and applying herbicides, you must review and follow herbicide labels and application rates; municipal, regional, provincial and federal laws and regulations; species-specific treatment recommendations, and site-specific goals and objectives.

Biological

There is no biocontrol available for this plant.