Propagation is by seeds sown soon after ripening or stratified and sown in spring and the stoloniferous species also by suckers; rare kinds are sometimes budded in summer on a common species or on Crataegus. | Propagation is by seeds sown soon after ripening or stratified and sown in spring and the stoloniferous species also by suckers; rare kinds are sometimes budded in summer on a common species or on Crataegus. |