Perennial Plant Trials at the Georgeson Botanical Garden

Abstract

Trials were begun in 1989 at the Georgeson Botanical Garden (64°51’N, 147° 52’W, elevation 475 feet; 136 meters) to evaluate the hardiness and ornamental potential of trees, shrubs, and herbaceous perennial ornamentals. Woody ornamentals are tested for 10 years, and herbaceous perennials for five years. This report is the first summary of perennials that have survived the trial period with a winter hardiness rating between zero and 2.5. Each plant in the trial is evaluated annually for winter injury and rated on a scale of zero through four. A zero rating denotes no visible injury, and four is death. A score of 2.5 and lower indicates the plant grew well in the Garden. It may have shown symptoms of winter injury but recovered in subsequent seasons. The species and cultivars listed in Table 1 are recommended for further trial throughout Interior Alaska. Plants are grown on a south-facing slope in Fairbanks silt loam soil. The plots have been cultivated since about 1910. All plants receive full sun except those located in the shade house. Plants receive supplemental irrigation, mostly hand weeding, and an annual application of 500 lb per acre (560.5 kg/ha) 10-20-20S fertilizer. Lilies receive 1500 lb (1,681.5 kg/ha) per acre of the same fertilizer. No plant receives winter protection such as mulches, wind barriers or snow fences. Weather data are compiled annually from U.S. Weather Service station (elevation 475 feet; 136 meters) located approximately 350 feet (105 meters) west of the Garden. A summary of pertinent weather statistics is shown in Table 2.