This is what the USDA has to say about this tree.

SILVAR' COYOTE WILLOW Scientific Name: Salix exigua Nutt. spp. exigua Common Name: Coyote willow
Cultivar Name: 'Silvar' Selected By: Pullman PMC, USDA-NRCS
Release Cooperators: USDA - Natural Resources Conservation Service, The University of Idaho-AES, Washington State University-ARC, Oregon State University-AES
'Silvar' coyote willow is a deciduous shrub originating from native plants growing along the the Tucannon River, near Starbuck, Washington at an elevation of 560 feet. Mature plant height is 22 feet and canopy width is 18 feet at Pullman, Washington. 'Silvar' is thicket forming, suckering, with pale blue-green silvery leaves and silvery pubescent twigs. The leaves are simple, entire, alternate and average four inches long, 5/16 inches wide, and are persistently hairy. Staminate and pistillate catkins appear after the first leaves. No disease or pest of this willow has been noted by the PMC. Willow pollen is an important food source in the spring for honeybees.

'Silvar' coyote willow grows in moist sands and gravel, with minor inclusions of sandy loam, and requires a minimum of 20 to 25 inches annual precipitation. Coyote willow will establish naturally by seed, however, the more common way is by hardwood cuttings taken in late winter.

'Silvar' is used in conservation for stream bank stabilization, riparian site restoration, bioengineering projects, wildlife habitat, and shelter belts. Other uses are for erosion control and promotion of native plant diversity.

For additional information contact: Wayne Crowder, Soil Conservationist or Scott Lambert (PMS), USDA-Natural Resources Conservation Service, Pullman Plant Materials Center (509) 335-7376 or e-mail crowder@wsu.edu.