Asexual Propagation of Salix humilis Using Stem Cuttings II: Stock Plant and Propagule Conditioning

Salix humilis Marsh. (prairie willow) is a compact shrub willow with a native distribution throughout the eastern United States. While underutilized in horticulture, prairie willow has potential for broader application in managed landscapes due to attractive ornamental features, hardiness, and high adaptability. This multifunctionality makes prairie willow a strong candidate for use in challenging settings, including urban green spaces. However, the unique recalcitrance of prairie willow to standard asexual propagation techniques and a general lack of directed research limits clonal improvement efforts and the availability of the species in the green industry. The objective of this work was to address this gap in knowledge and contribute to an effective asexual propagation protocol for prairie willow through four separate experiments exploring stock plant regeneration techniques, fungicide application, cutting positions, source populations, and substrate selection. Using cuttings [US Department of Agriculture (USDA)–Germplasm Resources Information Network (GRIN) and wild Minnesota populations] from stem tissue closer to basal regions of stock plants, applying preventive fungicide (T-Bird ® , 1.3 mL/L), and using a well-draining perlite or bark-based medium improved propagule rooting and survival. Rooting exceeded 80% in basal dormant cuttings treated with fungicide and apical cuttings rooted at near 0%. These findings can be used to identify propagation methods suitable for prairie willow commercial production, supporting its potential use in gardens and landscapes.