Purpleosier Alaska Blue Willow

You recognize purpleosier by its slender, supple branches bearing opposite or nearly opposite, narrowly oblong, lustrous dark blue-green leaves (5-10 cm long) that are pale or glaucous beneath. This broadleaf deciduous shrub or small tree reaches 8-10+ feet tall with multiple stems, displaying purplish young twigs that mature to light gray. In spring, you'll notice dense clusters of yellowish catkins. The plant's scientific name references the purplish coloring of young stems, and its supple stems have long been valued for basket and furniture making.

Purpleosier thrives in full sun in moist to wet soils, especially wet places that stabilize stream banks and erosion-prone areas. It prefers neutral to alkaline, anaerobic soils (tolerating wet conditions that would stress many plants), though it dislikes very acidic soils. The plant tolerates pollarding (annual hard heading to a framework) for foliage effect or size control. Fast-growing and vigorous, it can be pruned in late winter to early spring. Monitor for twig blight (Venturia), rust, Marssonina leaf and twig spot, bacterial twig blight, canker, crown gall, and wood decay. Various pests including borers, aphids, caterpillars, and scale insects have been documented in PNW records.