Hosta plantaginea and 11 selections with H. plantaginea parentage were chilled at 4C (39F) for 0, 1, 2, 3, or 4 weeks to determine the effect of chilling duration on subsequent plant growth. At 6 and 12 weeks after chilling treatment (WAT), response to chilling duration was selection dependent with three trends evident. At 6 WAT, eight of the 12 selections showed a decrease in new leaf formation with one or two weeks of chilling, but an increase in new leaf formation with additional chilling. In three of the 12 selections, new leaf formation increased linearly with increased chilling. New leaf formation of H. plantaginea ‘Grandiflora’ was not affected by chilling duration at 6 or 12 WAT. At 12 WAT, growth response of four of the 12 selections changed quadratically with increased chilling, similar to the response at 6 WAT, while leaf formation in seven of the 12 selections increased linearly with increasing chilling duration. At 18 WAT, leaf counts increased linearly in all H. plantaginea selections with increasing chilling duration, demonstrating increased vigor. All selections showed increases in new leaf formation over the 18-week period following chilling, demonstrating that chilling, though beneficial, was not required, and in the short-term, the response to chilling was selection dependent.
The authors would like to acknowledge Wade and Gatton Nurseries, Belleville, OH and Klehm's Nursery, Champaign, IL for donation of plant materials.
2Graduate Assistant, Professor, Associate Professor, Assistant Professor, and Laboratory Technician, respectively.