Yarrow (Achillea millefolium) is a common wildflower with medical properties and a rich folklore, which should be welcome in any garden. It belongs to the large sunflower family, Asteraceae, and is quite closely related to chamomiles. The most striking feature of Yarrow is the feathery fern- like leaves with finely cut segments which are quite characteristic. The name millefolium indicates the many segments of its foliage. It is sometimes called Milfoil and Thousand Weed. 

From June to September, the flowers appear which range from white through yellow to pale lilac. They look like tiny daisies, in flattened cymes (loose terminal heads). The whole plant is covered with varying degrees of closely pressed white silk- like hairs. The stem is angular and rough.

Yarrow has a reputation as a wound healer (vulnerary). This is borne out by its generic name; Achillea. When the warrior Achilles was injured in his weakened ankle, Yarrow was used to treat his wounds. The ancients referred to Yarrow as Herba Militaris, the military herb. The classic herbalist John Gerard tells us it is the same plant with which Achilles stanched the bleeding wounds of his soldiers. Yarrow makes an excellent wound healing ointment, with beeswax and olive oil. Essential oil of Yarrow is a beautiful pure blue colour on account of the component Chamazulene. It is particularly beneficial for allergies, skincare, stress-related conditions and insomnia. Photograph credit: Kristof Hegedus


Used internally Yarrow acts as a soothing relaxant to counteract cramps and spasms. Yarrow can bring on delayed menstruation, soothe painful periods and menstrual cramps and reduce excessive bleeding. Its bitter principles also support the digestive system admirably. Yarrow is even an effective anti-inflammatory and diuretic in cases of urinary infections, such as cystitis. A combination of Elderflower, Peppermint and Yarrow tinctures can be taken in equal parts to induce a sweat during the onset of colds & flu. Some individuals however are sensitive to plants in the Asteraceae family and may develop allergic reactions, so please only use under the guidance of a naturopath or medical herbalist. It also interacts with certain drugs.

Depending on the outlook of the gardener, Yarrow can be seen as an invasive weed of grass lawns, or as a welcome perennial of the flower border, rock garden, or wildflower meadow. When encouraged, yarrow plants grow 2- 4 ft tall, but low-growing varieties are also available. The main advantages of Yarrow as a garden plant are; (i) low maintenance, (ii) reproduces readily from seeds or by division, (iii) good for cut flowers and floristry, (iv) many varieties of form and colour are available (v) attracts butterflies & other insects, and (vi) Yarrow is highly durable and tolerates dry spells, low soil fertility and a variety of soil types. Although Yarrow thrives in hot, dry conditions and low soil fertility, it does not tolerate wet soils very well so this should be kept in mind during site selection. If you are interested in horticulture of wildflowers, ADL has many suitable courses to help.  Above image - Chamazulene:  Chemical Structure above; Essential Oil (right), Photograph credit:  Kristof Hegedus

References

Griffith-Jones, Joy. Schimacher, E.F. A Virtuous Weed. Blond & Briggs Publishers,1978
Grieve, Mrs M. A Modern Herbal. Dorset Press, 1992.
Mills, Simon Y. The Essential Book of Herbal Medicine. Arkana Publlishers, 1994.
Lavelle, Christine and Michael. The illustrated Practical Guide to Wildlife Gardening.
Anness Publishing, 2007

Achillea millefolium:  Summer Pastels from Thompson & Morgan