WASHINGTON (NEWSnet/AP) — Half of the U.S. now faces a slightly warmer climate than decades ago – resulting in redrawn maps that help guide gardeners and growers understand which plants will thrive in their regions.
The U.S. Department of Agriculture’s updated “Plant Hardiness Zone Map” was published Nov. 15, and it shows the impact that climate change is having on gardens and yards across the country.
It’s the first time in 10 years that the map was updated; reflecting the average lowest temperatures during the past 30 years.
The USDA said while established nurseries, Master Gardeners and extension services can provide more local assistance and tips, the maps “can facilitate the selection of appropriate perennial plants based on their observed performance.” Those recommendations might include which flowers, vegetables and shrub species are most likely to thrive in a particular area.
The hardiness zone codes are typically included with the descriptions of perennial plants in catalogs and other documentation, the USDA added.
“You wouldn’t want to plant plants that aren’t adapted right now for where you’re living,” said Theresa Crimmins, who studies climate change and growing seasons at the University of Arizona and was not involved in creating the map.
The changes don’t affect the country equally. On the new maps, the Midwest warmed more than the Southeast, for example.
Boston University plant ecologist Richard Primack, who was not involved in the map project, said the research shows “half the U.S. has shifted to a slightly warmer climatic zone than it was 10 years ago.” He called that “a very striking finding.”
Primack said he has noticed changes in his own garden: The fig trees are now surviving without extensive steps to protect them from winter cold. He has also spotted camellias in a Boston botanical garden and southern magnolia trees surviving the past few winters without frost damage. These species are all generally associated with warmer, more southern locations.
The Associated Press contributed to this report. Copyright 2023 NEWSnet and The Associated Press. All rights reserved.