Medicinal plants of old, now glories of the garden
Yarrow takes on delicate color and a dramatic profile in ‘Appleblossom’, one of the Galaxy Hybrids.
• Learn More: A Guide to Yarrow Varieties
Common yarrow grows wild in fields, meadows, and dry wastelands, and I often see its dirty white flowers alongside country roads here in Oregon. This is the herb whose leaves the Greek hero Achilles reputedly bound on his soldiers’ battle wounds to stop the bleeding during the Trojan War, whose stripped stalks the Chinese tossed to divine the future, whose tops the Swedes used to flavor their beer. For centuries, healers in various cultures have recommended it as a cure for dozens of ailments.
As a garden subject, common yarrow (Achillea millefolium) leaves a lot to be desired. It’s weedy and invasive, and its muddy white or pink flowers are unattractive. If you’ve balked at adding this herb to your garden, you may be happy to learn that breeders have recently expanded its color range to include clear whites, carmines, and an assortment of pinks and lilacs in between—lovely colors that will grace any garden. And common yarrow has many gardenworthy relatives, including those with flowers in classic yellows and golds.
The genus Achillea (named in honor of Achilles) comprises some eighty-five species native to the North Temperate Zone. More than half have been grown in gardens. Most have soft, often aromatic, fernlike foliage that is evergreen except in the coldest climates. Creeping rhizomes tend to form mats of foliage, and some forms can be quite invasive. Erect stems from 2 inches to 5 feet tall support flat-topped clusters of small, often densely packed, daisylike flowers. All species require a sunny location and well-drained soil. Established plants of many species are drought tolerant, although some species prefer moister soil. Many of the larger yarrows tolerate salt spray.
The native habitats of yarrows range from dry or wet lowland areas to alpine rocks and meadows. Most species prefer acid soil, but some tolerate a soil pH up to 7 (neutral), and a few must have alkaline soil. Yarrows are among the few herbs that support the contention that herbs thrive in poor, infertile soils. Applications of manure or other fertilizer, too much shade, or summer night temperatures above 70°F all can cause weak stems that are likely to flop over under the weight of the flower heads. Plants grown under such conditions are short-lived and are less hardy than plants grown in poorer soils.
Nearly all yarrows are carefree, pest-free, and winter-hardy in USDA Zones 3 to 9. The finely divided leaves of some species trap moisture and make these plants prone to mildew in hot and humid regions. I divide the clumps every three to four years (every other year for A. ptarmica and A. tomentosa) to renew their vigor; a sharp shovel is handy for curbing the more vigorous species. Where summers are short and relatively cool, removing spent blooms promptly will encourage and prolong summer blooming well into autumn.
I propagate my yarrows either by division or cuttings in the spring or fall. Although yarrow seeds germinate readily in about two weeks, cultivars are unlikely to come true from seed, so I recommend this method only for the species.
One of the pleasures of growing yarrows is watching the many species of butterflies that come to the flowers for nectar. The flowers also attract lady beetles and tiny parasitic wasps that prey on aphids. The English herb writer Lesley Bremness asserts that even a single leaf of common yarrow placed in a compost pile will speed decomposition. Doesn’t that sound too good to be true? I shall have to try it this fall.
Yarrows are very popular both as fresh-cut flowers and for drying. Once dried, the yellow-flowered yarrows such as ‘Coronation Gold’, ‘Gold Plate’, and ‘Cloth of Gold’ are virtually indestructible, lasting for years with minimal fading. They were for many years mainstays of dried herbal arrangements. Today, however, the pastels seem to be more popular among flower arrangers than the bright yellows. Unfortunately, the flowers of many of the new pastel cultivars fade dramatically on drying, though sometimes these muted colors are still quite beautiful. I wait until the petallike rays of each minute floret are touching those of neighboring florets and the pollen is visible before cutting flowers for fresh or dried use. If picked too early, the stems will flop, or the flower head will be an unsightly myriad of tiny shriveled flowers.
Modern science has confirmed at least some of common yarrow’s medicinal uses. Of more than forty constituents isolated from it, azulene, a hydrocarbon, is anti-inflammatory, and achilleine, an alkaloid, improves blood circulation. The tops are harvested when in flower (May to September) for use as a digestive or tonic.
Common yarrow may be grown as an herbal lawn that is soft on your feet and easy to care for. If mowed about three times a year to prevent flowering, the lawn will stay green and fresh-looking year round. It will withstand light foot traffic, and the yarrow will eventually choke out any weeds. Sow seed in late summer or spring, using 1/2 pound per 100 square yards. Spread it uniformly and press lightly into a prepared bed (no fertilizer!) with a lawn roller.
Yarrow is often an ingredient in ecological lawn seed mixtures. Premier Botanicals, Ltd., a breeder of lavenders in Albany, Oregon, has used common yarrow very effectively as a ground cover to prevent erosion on a sloping bank, and it is highly recommended for stabilizing sand dunes. It’s also suitable for a “wild” garden or unimproved site, where its vigorous habit will be an asset rather than a nuisance.
• André Viette Farm and Nursery, Rt. 1, Box 16, Fisherville, VA 22939. Catalog $6.
• Carroll Gardens, 444 E. Main St., PO Box 310, Westminster, MD 21157. Catalog $3.
• Companion Plants, 7247 N. Coolville Ridge Rd., Athens, OH 45701. Catalog $2.
• Forestfarm, 990 Tetherow Rd., Williams, OR 97544-9599. Catalog $3.
• Goodwin Creek Gardens, PO Box 83, Williams, OR 97544. Catalog $1.
• A High Country Garden, 2902 Rufina St., Santa Fe, NM 87505-2929. Catalog free.
• Logee’s Greenhouses, 141 North St., Danielson, CT 06239. Catalog $3.
• Milaeger’s Gardens, 4838 Douglas Ave., Racine, WI 53402-2498. Catalog $1.
• Richters, Goodwood, ON, Canada L0C 1A0. Catalog free.
• Sandy Mush Herb Nursery, Rt. 2, Surrett Cove Rd., Leicester, NC 28748. Catalog $4.
• Siskiyou Rare Plant Nursery, 2825 Cummings Rd., Medford, OR 97501. Catalog $3.
Andy Van Hevelingen and his family grow herbs in Newberg, Oregon. He is a frequent contributor to The Herb Companion.
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