In November 2014, Amy Bartow emailed the listserv to describe very high germination rates (80% within two weeks) for Kincaid’s lupine following mechanical scarification. In her experience, previous lots of Kincaid’s lupine seed had required about 8 weeks in a cooler before germinating, with sporadic germination continuing for months. She wondered whether more aggressive scarification methods would improve germination and asked for input from others who had experience with this species.
Steve Erikson replied that in his experience with many species in the Lupine genus, the primary dormancy mechanism is a hard seed coat that can be broken through scarification, softening or potentially heat, but that some species or individuals may require cold treatment. David Perasso agreed, adding that he had not found any lupine species that require cold dormancy. Tom Kaye (Institute for Applied Ecology) replied with a similar pattern to Amy Bartow – Kincaid’s Lupine seeds had previously required cold stratification but now seemed to germinate more rapidly. He added that in other species, the need for cold stratification has varied by year, even within the same wild populations, and noted that other researchers have found effects of environmental conditions on dormancy rates. David Perasso added that many variables play into seed germination rates and that scarification should be verified by soaking seeds in water overnight to see if they swell up.