Journal of the American Society for Horticultural Science · 1969 · 16 citations · 0 references
AgriculturePlant BiologyPlant SciencesCrop PhysiologyPlant EcophysiologyPlant PhysiologyCold HardinessCold Stress PhysiologyFreezing InjuryRoot EcologyRoot PhysiologyRooting PhysiologyAcclimation MechanismsCold Hardiness PhenotypingFreezingPlant Cold Stress PhysiologyRoot Cold HardinessRoot Injury SymptomsRoot Response To TemperatureSoil Temperature Effects On Establishment
Abstract Roots of container grown ‘Hetzi’ juniper developed cold hardiness to -10°C on December 2, 1963 in St. Paul, Minnesota as determined by controlled freezing tests. The temperature of container soil, under natural conditions, did not fall below 0° until after December 2. Once frozen, the soil temperature responded rapidly to falling ambient temperatures. Container soil temperatures of -10° occurred several times after December 2 resulting in root injury. Tops developed cold hardiness from -15°C on September 11 to greater than -39° on December 2, 1963. No top injury occurred at any stage during the study. Winter injury common to container grown Hetzi Juniper in Minnesota is apparently root injury.