Characteristics

• Appearance: The plant features aromatic, feathery, fern-like foliage and blooms with dense clusters of small flowers in flattened, corymb-like arrays.
• Flowers: The flowers are typically white but can also be pink, red, or yellow in cultivated varieties. They bloom throughout the summer and attract pollinators like butterflies and bees.
• Growth habit: Yarrow is a fast-spreading, rhizomatous perennial that can grow up to 3 feet tall and wide. It is considered weedy by some due to its vigorous spreading via both rhizomes and seeds.
• Habitat: It is native to temperate regions of the Northern Hemisphere and is found in disturbed areas such as fields, meadows, and roadsides. 

Growing conditions and care

• Sunlight: Yarrow thrives in full sun, which promotes compact growth and abundant blooms.
• Soil: It prefers lean, well-drained soil and is tolerant of poor soils, as long as drainage is good. Overly rich soil can cause the stems to flop.
• Watering: This plant is drought-tolerant once established and does not require much water. Overwatering can lead to root rot.
• Maintenance:
  • Deadheading spent flowers can encourage reblooming.
  • Because it spreads aggressively, common yarrow may need to be contained or divided every 2–3 years to maintain its vitality.
  • For ornamental gardens, cultivated varieties with more upright habits may be a better choice. 

Medicinal and traditional uses

• Historical significance: The genus name Achillea comes from the mythical Greek character Achilles, who reportedly used the plant to treat soldiers' battle wounds. This gave rise to one of its common names, "soldier's woundwort".
• Traditional remedies: Native American and other indigenous cultures used yarrow to treat ailments like headaches, colds, burns, and wounds.
• Herbal properties: Yarrow has been used as an astringent, anti-inflammatory, and diaphoretic (induces sweating). It contains compounds such as flavonoids, alkaloids, and terpenes.
• Modern uses: Today, yarrow is still used in herbal medicine for digestive issues, inflammation, and wound healing, though scientific evidence for many of its uses is still developing. 

Toxicity and precautions

• Allergies: People with allergies to other plants in the Asteraceae family, such as ragweed, may have a reaction to yarrow.
• Toxicity to pets: Yarrow is toxic to cats, dogs, and horses. Ingestion can cause vomiting, diarrhea, depression, and other symptoms.
• Contact dermatitis: Wearing gloves is recommended when handling yarrow, as it can cause allergic skin rashes in some people. 

Culinary use

• Yarrow was a popular vegetable in the 17th century and can be used as a spice or in tea. It has a sweet but bitter taste.
• In the Middle Ages, it was used to flavor beer, a practice known as gruit ale.