Yarrow

Achillea millefolium subsp. var.	Yarrow, Milfoil
	Habit: herbaceous Height: ⇕ to Width: ⇔ to .2m1m .45m.75m Height: ⇕ .2 m to 1 m Width: ⇔ .45 m to .75 m Lifespan: ⌛ perennial Origin: ✈ Poisonous: ☠ rare skin allergies Bloom: ❀ early summer, mid summer, late summer	Exposure: ☼ sun, part-sun, shade Water: ◍ moderate, dry Features: ✓ flowers, fragrance, naturalizes, invasive, bees, drought tolerant, ground cover, fire resistant Hidden fields, interally pass variables to right place Minimum Temp: ☃ -25°C248.15 K -13 °F 446.67 °R USDA Zones: 3 to 10 Sunset Zones: Flower features: ❀ red, yellow, white
	Asteraceae > Achillea millefolium var. , L.

Yarrow (Common Yarrow, Gordaldo, Nosebleed plant, Old Man's Pepper, Sanguinary, Soldier's Woundwort, Thousand-leaf, Thousand-seal; Achillea millefolium) is a flowering plant in the family Asteraceae, native to the Northern Hemisphere.

Common yarrow is an erect herbaceous perennial plant that produces one to several stems (0.2 to 1m tall) and has a rhizomatous growth form. Leaves are evenly distributed along the stem, with the leaves near the middle and bottom of the stem being the largest. The leaves have varying degrees of hairiness (pubescence). The leaves are 5–20 cm long, bipinnate or tripinnate, almost feathery, and arranged spirally on the stems. The leaves are cauline and more or less clasping. The inflorescence has 4 to 9 phyllaries and contains ray and disk flowers which are white to pink. There are generally 3 to 8 ray flowers that are ovate to round. Disk flowers range from 15 to 40. The inflorescence is produced in a flat-topped cluster. Yarrow grows up to 3500m above sea level. The plant commonly flowers from May through June, and is a frequent component in butterfly gardens. Common yarrow is frequently found in the mildly disturbed soil of grasslands and open forests. Active growth occurs in the spring.

Common yarrow is a drought tolerant species of which there are several different ornamental cultivars. Seeds require light for germination, so optimal germination occurs when planted no deeper than ¼ inch. Seeds also require a germination temperature of 18 - 24 C. Common yarrow responds best to soil that is poorly developed and well drained. The plant has a relatively short life, but may be prolonged by dividing the plant every other year, and planting 12 to 18 inches apart. Common yarrow is a weedy species and can become invasive. It may suffer from mildew or root rot if not planted in well-drained soil.

Standard Cyclopedia of Horticulture

Achillea millefolium, Linn. Milfoil. Yarrow. Height 1-3 ft.: lvs. bipinnately parted, segms. linear, 3-5 cleft: fls. in flat corymbs. June-Oct. Eu.,Asia, Amer. Common in pastures. — Less commonly cult., than vars. rubrum and roseum, with red or purple fls. CH The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.

Cultivation

Succeeds in most soils and situations but prefers a well-drained soil in a sunny position[1, 14]. Shade tolerant[13]. Plants live longer when grown in a poor soil[200] and also do well on lime[208]. Established plants are very drought tolerant[200], they can show distress in very severe droughts but usually recover[190]. It remains green after grass has turned brown in a drought[187]. Plants succeed in maritime gardens[233]. The plant has a very spreading root system and is usually quite invasive[233, K]. A very hardy plant, tolerating temperatures down to about -25°c[187]. Yarrow is an excellent plant for growing in lawns, meadows, orchards etc., it is tolerant of repeated close cutting and of being walked on[20, 54]. It works to improve the soil fertility[20, 54]. A very good companion plant, it improves the health of plants growing nearby and enhances their essential oil content thus making them more resistant to insect predations[14, 18, 20, 53]. There are some named forms, selected for their ornamental value[183, 238]. 'Pink' (syn. 'Rosea') has very aromatic foliage and deep pink flowers[183]. Hybridizes freely with other members of this genus[200]. A good bee plant, it is an important nectar source for many insects[24].

Propagation

Seed - sow spring or early autumn in a cold frame[133]. The seed usually germinates in 1 - 3 months[133]. When large enough to handle, prick the seedlings out into individual pots and plant them out in the summer. Division in spring or autumn. Very easy, the divisions can be planted direct into their permanent positions. Divisions succeed at any time of the year. Basal cuttings of new shoots in spring. Very easy, collect the shoots when they are about 10cm tall, potting them up individually in pots and keeping them in a warm but lightly shaded position. They should root within 3 weeks and will be ready to plant out in the summer.

Varieties

The species is generally too weedy for gardens but cultivars include 'Paprika', 'Cerise Queen' and 'Red Beauty'; and the many hybrids of this species designated Achillea x taygetea including 'Appleblossom', 'Fanal' and 'Hoffnung' are useful garden subjects.

There are several varieties and subspecies:

• Achillea millefolium subsp. millefolium
  • Achillea millefolium subsp. millefolium var. millefolium - Europe, Asia
  • Achillea millefolium subsp. millefolium var. alpicola - Rocky Mountains
  • Achillea millefolium subsp. millefolium var. borealis - Arctic regions
  • Achillea millefolium subsp. millefolium var. californica - California
  • Achillea millefolium subsp. millefolium var. occidentalis - North America
  • Achillea millefolium subsp. millefolium var. pacifica - west coast of North America
  • Achillea millefolium subsp. millefolium var. puberula - California
  • Achillea millefolium subsp. millefolium var. rubra - Southern Appalachians
• Achillea millefolium subsp. chitralensis - western Himalaya
• Achillea millefolium subsp. sudetica - Alps, Carpathians

Gallery

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References

• Plants for a Future - source of some creative commons text
• Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963

External links

• w:Yarrow. Some of the material on this page may be from Wikipedia, under the Creative Commons license.
• Yarrow QR Code (Size 50, 100, 200, 500)