About Those New USDA Hardiness Zone Maps

The USDA has released new and more accurate zone hardiness maps. These maps show the average minimum temperature for a given area, thus providing important guidelines for gardeners. Last updated in 1990, the new map allows searches by zip code or state. While the prior map identified the Boston Metrowest area as a zone 5, this new map redefines this area as zone 6. The USDA states that zone boundaries have increased about 5 degrees, but "are not reliable evidence of whether there has been global warming."

OK, fine. Now what does this mean for us in Boston Metrowest? Well my fellow plant lovers, we can expand our plant palettes! I am usually conservative about plant recommendations, ensuring the selections are sure to survive our winters.  However, this new hardiness map confirms my suspicions about the relative tenderness of many plants that I have previously confined to microclimates. Also, many of the growers are sure to reach out to our area nurseries with introductions that they will warrantee and therefore make it less risky for us to introduce to our landscapes. Stay tuned...

Check out the maps at http://planthardiness.ars.usda.gov/PHZMWeb/