16/11/2023
USDA’s new plant hardiness zone map released today, which reflects average temps over the past 30 years. This updates the previous version, from 2012, and notably sees many zone changes due to warming climate. Our zone in Northern VA has shifted from 7a to 7b (or 8a for spots closer to the city like Arlington).
New USDA hardiness zone map released today ‼️ Besides checking to see if your zone has officially changed, there is a lot to explore here! This map includes two new zones and a finer level of detail.
The NEW hardiness zone map is based on 30-year averages (1991 to 2020) for the lowest annual winter temperatures within specified locations. The 2012 edition was based on averages from 1976 to 2005.
Low temperature during the winter is a crucial factor in the survival of plants at specific locations.
New zones: 12 and 13 have been introduced for regions with average annual extreme minimum temperatures above 50 degrees and 60 degrees F, respectively. They appear only on the maps for Hawaii and Puerto Rico.
The new map(s) were jointly developed by Oregon State University's PRISM Climate Group and the USDA's Agricultural Research Service, and it is the most accurate and detailed USDA has ever released.
https://planthardiness.ars.usda.gov/