• IMPORTANCE TO LIVESTOCK AND WILDLIFE
• PALATABILITY
• NUTRITIONAL VALUE
• COVER VALUE
• VALUE FOR REHABILITATION OF DISTURBED SITES
• OTHER USES AND VALUES
• MANAGEMENT CONSIDERATIONS

IMPORTANCE TO LIVESTOCK AND WILDLIFE:

Western yarrow varies greatly in forage value, depending on locality and seasonal development. It is generally unpalatable, although domestic livestock and wildlife occasionally consume the flowers. Cattle and horses usually do not graze western yarrow, but bighorn sheep, pronghorn, and deer may use it. They most often graze the flowerheads. Western yarrow provides fair forage for domestic sheep and goats [24,43]. The average summer use is 20% for cattle and horses and 40% for domestic sheep and goats [58]. Western yarrow is an important food of 4- to 8-week-old sage grouse chicks [16].

Western yarrow contains volatile oils, alkaloids, and glycosides but is not generally considered a toxic plant because it is so seldom consumed by livestock. Milk from cows consuming western yarrow has a "disagreeable" flavor [64].

PALATABILITY:

The palatability of western yarrow to livestock and wildlife in several western states has been rated as follows [27]:

                     CO      MT      ND      UT      WY
Cattle              poor    poor    poor    poor    poor
Domestic sheep      fair    fair    fair    good    fair
Horses              poor    poor    poor    poor    poor
Pronghorn           ----    poor    fair    fair    fair
Elk                 ----    poor    ----    fair    fair
Mule deer           ----    poor    fair    fair    fair 
White-tailed deer   ----    poor    poor    ----    fair
Small mammals       ----    poor    ----    fair    fair
Small nongame birds ----    poor    ----    fair    poor         
Upland game birds   ----    poor    ----    fair    good
Waterfowl           ----    ----    ----    poor    poor

NUTRITIONAL VALUE:

Western yarrow is rated as poor in energy and protein content [27]. In Northern Utah, plants growing on unfavorable sites (defined by slope, exposure, and vegetation cover) were 9% higher in crude protein than plants growing on favorable sites [21]. Mean percent (+/- S.D.) monthly nutrient values and moisture content of western yarrow collected from Cold Meadows in the River of No Return Wilderness, Idaho, (1977 to 1978) were as follows [29]:

 
                June        July           Aug 
crude fiber    22(2.0)     24(1.8)       25(1.2)
crude protein  20(1.6)     17(0.3)       14(0.9)
moisture       78(5)       64(2)         58(3)
CA:P           2.7:1       4.5:1         5.1:1

COVER VALUE:

The degree to which yarrow provides cover for wildlife has 
been rated as follows [27]:

                       CO      MT      ND      UT      WY
Pronghorn             ----    ----    fair    poor    poor
Elk                   ----    ----    ----    poor    poor
Mule deer             ----    ----    fair    poor    poor
Small mammals         good    poor    ----    fair    poor
Small nongame birds   good    poor    fair    fair    poor
Upland game birds     ----    poor    ----    fair    poor
Waterfowl             ----    ----    ----    poor    poor
White-tailed deer     ----    ----    fair    ----    poor

VALUE FOR REHABILITATION OF DISTURBED SITES:

Due to its extensive system of rhizomes, western yarrow is a good soil binder [59] and has been used in erosion control projects on the Wasatch Plateau in central Utah [69]. In Massachusetts, seed-grown sod of western yarrow, along with sod of 11 other species, was transplanted onto a roadside site with shallow, infertile soil and direct exposure. After 4 years, western yarrow was one of 3 surviving species on the site [2].

OTHER USES AND VALUES:

Native Americans used tea made from western yarrow to relieve ear-, tooth-, and headaches; as an eyewash; to reduce swelling; and as a tonic or stimulant. Western yarrow varies in taste and in potency depending on where it grows and at what stage of growth it is in. The best time to collect yarrow for tea is right before the flowers are produced, using only the new succulent leaves [34]. During the Civil War, western yarrow was widely used to treat wounds and became known as "soldiers' woundwort." An ethanol extract of western yarrow has mosquito- repelling properties [67].

Western yarrow is used for summer and winter bouquets. When cut fresh and kept in water, western yarrow flavors the air with an aromatic spiciness [43,64].

MANAGEMENT CONSIDERATIONS:

Western yarrow tends to increase rapidly in disturbed areas or overgrazed rangelands, replacing more valuable forage species and crops [43]. It is often an indicator of past overstocking and excessive utilization [69]. Western yarrow tends to decrease on grazing plots once grazing has ceased [7,20]. Since rhizomes are a major means of western yarrow regeneration, starting control measures early in autumn may prevent spring growth from autumn and winter rhizome dry matter [15]. In New Zealand, barley (Hordeum vulgare) reduced rhizome and seed production in western yarrow [15]. Dicamba and mixtures with triclopyr are effective in controlling western yarrow [74].

Related categories for SPECIES: Achillea millefolium | Western Yarrow