Response of American and European elderberries to extreme winter temperature in North Central Ohio

摘要

When managing American elderberry (Sambucus nigra L. ssp. canadensis (L.) R. Bolli [Capri-foliaceae]) and European elderberry (Sambucus nigra L. ssp. nigra) in northern latitudes, growers should consider species selection and placement to overcome unusual freezing events. In North Central Ohio, cultivars of American elderberry recovered more robustly from 2 consecutive polar vortices than did cultivars of European elderberry species. A trial planting of established Sambucus spp. were exposed to verylow winter temperatures during freezing events of 2014 and 2015. Both species suffered severe winter dieback each year. American elderberry recovered by the second yearfollowing the freezing events. The winter-kill of European elderberry was cumulative over both freezing event years. European elderberry died back successively each year with total kill of younger plants and significant dieback of mature shrubs. American elderberry nominally recovered the spring following the first freeze but recovered completely by the second year after the freeze events. Because of the growth characteristics of European elderberry, there was little to no recovery from the trunk or base. Mature specimens regrew from root sprouts over a period of 3 y; original specimensof European elderberry never fully occurred.