Now, for the first time since 1990, gardeners have an updated, comprehensive climate zone guide for plant hardiness. The U.S. Department of Agriculture has just released a new interactive map based on weather data gathered from 1976 to 2005. The map proves what gardeners have long suspected: there has been a warming trend in many parts of the country, affecting plant variety, range, and adaptability.
Since the average minimum temperature has gone up in many areas, spring comes sooner, fall lasts longer, and winters are often milder. Many parts of the country have gone up half a zone, based on 10 degrees Farenheit for each latitudinal zone. My zone, for example, had been 6b; now it’s 7a.
You can enter your zip code here at the new USDA map to find which zone you’re in, and to learn more about the USDA’s research process.