I like to joke that for us East-siders, the Washington state evergreen is actually big sagebrush (Artemesia tridentata), not the legislature-adopted Douglas-fir tree. In our arid region of low rainfall, cold winters and hot dry summers, big sagebrush grows 5-8 feet tall, forming a canopy above a sea of grasses, smaller shrubs, and wildflowers. Wildlife species from birds to mammals to insects utilize sagebrush for food, shelter, and nesting materials. Eighteen different species of sagebrush are abundant yet under appreciated by many of us who inhabit its range across much of western North America. I nominate today to be “sagebrush appreciation day.”
Big sagebrush plants have some interesting adaptions that allow them to thrive in a seemingly harsh environment. They have small evergreen leaves that are covered with fine hairs that trap moist air next to minimize water loss, and reflect outward damaging UV light. These leaves photosynthesis all year round, supporting continued slow growth of the woody shrub. In early spring, longer, larger strap-shaped leaves grow, able to capture sunlight and maximize food production. By mid-summer, these leaves turn yellow and are shed.
Crushed leaves have a pungent odor we all recognize as the smell of “home.” These plant-made chemicals are made in leaf glands, some of which deter insects and others actually attract grazing animals. Sagebrush blooms and set seeds in the fall, causing many of us to sneeze due to wind-born pollen from the flowers! Seeds are important source of winter food for wildlife.
Big sagebrush grows in deep (at least 1-foot) well-drained soils and has two types of roots. Net-like near-surface roots radiate out in all directions, at the ready to absorb rainfall and snowmelt. A large, deep taproot grows many feet down, accessing groundwater unavailable to more shallow-rooted neighboring plants. To homesteaders, big sagebrush indicated good farming soils. Much of our region’s historic sagebrush lands were plowed and converted to crops.
Today, many government ad conservation organizations are working together to both conserve and restore sagebrush habitats. Chelan-Douglas Land Trust has started a multi-year restoration project on the Horse Lake Reserve to convert old wheat fields back to a native plant community of sagebrush, bunches grasses, and wildflowers. This will provided improved winter range for mule deer and a myriad of other wildlife species.
By looking closely at leaves and soils, you can easily identify the other two common sagebrush species in our foothills. Three tip sagebrush (Artemisia tripartite) has deeply incised 3-lobed leaves and grows in deep soils, often alongside big sagebrush but smaller in size. Scabland sagebrush (Artemisia rigida) is very low-growing on rocky soils, also with deeply incised 3-lobed leaves that are silvery in appearance. Scabland sagebrush is deciduous, loosing all of its leave in the fall.
A 2012 free 85-page booklet, “Pocket Guide to Sagebrush,” is available for download at: http://www.sagestep.org/pubs/brushguide.html