Overcoming seed dormancy in 2 Rocky Mountain native shrubs: Ceanothus velutinus and Cercocarpus montanus

Abstract

Ceanothus velutinus Douglas ex Hook. (snowbrush ceanothus [Rhamnaceae]) and Cercocarpus montanus Raf. (alderleaf mountain mahogany [Rosaceae]) are native species with urban landscape value and potential to create unique aesthetics as well as to conserve water. Propagation protocols for these native species are not well established. Because of dormancy, seed propagation requires scarification and (or) stratification. We designed a study to further define protocols necessary to consistently produce high rates of germination for these 2 species. Ceanothus velutinus seeds were scarified in hot water at 50, 70, or 90 °C (122, 158, or 194 °F) and soaked with gibberellic acid (GA₃) at 0, 50, 250, or 500 mg/l (0, 50, 250, or 500 ppm) for 24 h before stratification for 1, 2, or 3 mo. Seeds of C. velutinus stratified for 2 mo after being scarified at 90 °C and treated with 500 mg/l (500 ppm) GA₃ had the greatest germination percentage (74.2 ± 2.0%). Percent germination was the lowest when seeds were scarified at 50 °C (122 °F) and treated without GA₃ but with 2 mo stratification. Cercocarpus montanus seeds were treated with GA₃ at 0, 50, 250, or 500 mg/l (0, 50, 250, or 500 ppm) and stratified for 1, 2, or 3 mo. Seed germination of C. montanus increased as stratification time increased. Seeds dipped in 50 mg/l (50 ppm) GA₃ and stratified for 2 mo had the greatest germination percentage (64.2 ± 3.6%).

Paudel A, Sun Y, Rupp LA, Carman J, Love SL. 2020. Overcoming seed dormancy in 2 Rocky Mountain native shrubs: Ceanothus velutinus and Cercocarpus montanus. Native Plants Journal 21(3):353–358.