Share This Article
Pine Hollow Arboretum is one of many botanical gardens rethinking their planting strategies as the climate warms. These strategies range from testing out new, warmth-loving plants to putting more resources toward pest and invasive species management.
The U.S. Department of Agriculture recognizes 13 plant hardiness zones based on a region’s coldest annual temperatures, averaged over a period of 30 years. These zones guide gardeners’ planting decisions by advising which species of plants, especially perennials, are most likely to thrive in a specific zone.
Scientists compared 30-year coldest temperature averages from the past (1951–1980) and present (1995–2024) at 247 locations across the United States using NOAA’s Applied Climate Information System dataset. They found that 67% of locations have shifted to warmer zones since the 1951–1980 period.
The models predict that the mid-century average annual coldest temperatures during the 2036–2065 time period will warm in 100% of the country by an average of 3.1°C (5.6°F). Coldest annual temperatures in the Upper Midwest, Alaska, the Northern Rockies and Plains, and the Northeast and Ohio Valley were projected to warm the most.
