Achillea millefolium L.
Achillea millefolium, commonly known as common yarrow, is a perennial.
Achillea millefolium was described by Carl Linnaeus in 1753. The name is considered as validly published.
The name of the genus alludes to Achilles, the fabled hero of the Trojan war, who discovered it as medicinal plant and supposedly used it as a vulnerary drug (Iliad, 11. song, vers 822ff.), the species name millefolium (thousand-leaf) describes the finely dissected leaves.
The perennials have a prostrate growth and reach heights of 20 to 120 centimetres. The plants reach a width of 0.6 to 1 metres.
Achillea millefolium is semi-deciduous. The dark-green, simple leaves are alternate. They are lanceolate with pinnatisect margins and pinnate venation. The surface of the leaves is glabrous to tomentose.
Flowers and Fruits
Achillea millefolium produces corymbs of white many-stellate flowers from May to July.
- Some variations occurring in natural habitat
The perennials produce brown achenes in summer.
The plants form rhizomes.
Achillea millefolium is native to the whole of Europe, Turkey, the Caucasus, Iran, the Himalaya, West-Siberia and Central Asia and is naturalized in North America, Australia and New Zealand. The plants occur on plains as well as right up to high mountains and can be found in nutrient-rich meadows, semi-arid grasslands and waysides. They are soil stabilizers and nutrient indicators for nitrogen.
The perennials prefer a sunny situation on dry soil but do not tolerate droughts. They prefer loamy or sandy-loamy soil with a pH between 6 and 8. They grow well on nutrient-rich soils but will grow too fast thus becoming unstable. Better are nutrient-poor, freely draining soils. The plants need a soil depth of at least 20 centimetres for good growth. They tolerate temperatures down to -35Â°C (USDA zone 4).
Classification after Prof. Dr. Sieber:
- open areas
Tolerance of special soil conditions
- none: anaerobic soil, drought
- low: calcareous soil
- high: city climate
The recommended planting distance is 40 centimetres, the perennials are best planted in groups of 3 to 5. Suited for roof greening and for beds and borders, as well as suited as cut flowers and as bee pasture. Good plant neighbours are e.g. Salvia nemorosa, Centranthus ruber, Artemisia ludoviciana, Stachys bycantina, Calamintha nepeta, and various grasses.
Maintenance and Propagation
The plants need little to no maintenance if grown under suitable conditions.
- Remove runners if no spreading is desired.
- Cut back all shoots considerably after flowering to promote healthy growth.
Propagate by sowing. Colour variation may occur when propagating cultivars by sowing, in that case propagate by cuttings or by division.
Images of more Achillea millefolium cultivars.
The sap may slightly irritate the skin.
Please read the health issues note!
Pests and Diseases
A powdery white coat on the plants indicates an infection with powdery mildew. Remove affected plants and apply a fungicide. To prevent infection improve ventilation, keep the roots moist and do not water the plants from above.
White tufts or white covering on the lower surface of the leaves indicates an infection with downy mildew. Remove affected plants and apply a fungicide. To prevent infection improve ventilation, keep the roots moist and do not water the plants from above.
Brown, orange or yellowish pustules on shoots and on the leaves lower surfaces are very likely caused by a fungal infestation (rust). Remove affected parts and apply fungicide. Also improve ventilation and reduce humidity.
- Walter Erhardt, Erich GĂ¶tz, Nils BĂ¶deker, Siegmund Seybold: Der groĂe Zander. Eugen Ulmer KG, Stuttgart 2008, ISBN 978-3-8001-5406-7. (Ger.)
- Christoper Brickell (Editor-in-chief): RHS A-Z Encyclopedia of Garden Plants. Third edition. Dorling Kindersley, London 2003, ISBN 0-7513-3738-2.