USDA Map Update Shifts Beaufort County to zone 8a-8b

The U.S. Department of Agriculture (USDA) updated its "Plant Hardiness Zone Map" this week. This map is the national standard for gardeners and growers to figure out which plants are most likely to survive the coldest winter temperatures in their location, which is information directly relevant for beekeepers and other people working with pollinators.

Beaufort County now falls in 8a-8b. Most of the coastal regions of eastern NC are now zone 8b, with inland and northern areas of eastern NC remaining in zone 8a. The previous version of the map was released more than a decade ago in 2012, and the one before that was from 1990. The 2012 map has Beaufort County in 8a only, and the 1990 map indicated 7b-8a.

The 2023 map is about 2.5º Fahrenheit (1.4º Celsius) warmer than the 2012 map across the contiguous U.S., says Chris Daly, director of the PRISM Climate Group at Oregon State University that jointly developed the map with the USDA.

Daly says the new map means about half the country has shifted into a new half zone and half hasn't. In some locations, people may find they can grow new types of flowers, fruits, vegetables and plants.

The scientific community overwhelmingly agrees that humans burning fossil fuels like oil, coal and gas is the primary driver of global warming. The summer of 2023 was the hottest meteorological summer on record for the northern hemisphere, according to the National Oceanic and Atmospheric Administration.

Daly is hesitant to explicitly attribute the specific changes from the 2012 map to the 2023 map to climate change because of the volatility of the key statistic they used to create this map. They were mapping "the coldest night of the year, each year, over the past 30 years", which Daly says can be a highly variable figure.

In an email, a press officer for the USDA says, "Changes to plant hardiness zones are not necessarily reflective of global climate change because of the highly variable nature of the extreme minimum temperature of the year."

But Daly also stated, in the big picture, climate change is playing a role in changing what grows where in the US. "Over the long run, we will expect to see a slow shifting northward of zones as climate change takes hold."