Hardiness Zone Changes

Here's the new Hardiness Zone map for the lower 48, courtesy of arborday.org.  This map has some significant differences from the 1990 map.  The biggest differences are out west.  Areas in the desert southwest have actually lowered a zone (indicating cooler temperatures), while areas west of the central Rockies have increased up to two zones (indicating warmer temperatures); maps of those differences are available at arborday.org. 

Here in northeastern New Jersey, we have gone from zone 6 to zone 7.  What does that mean?  First, we are in the same zone as Oklahoma City, which highlights the moderating influence of the Atlantic Ocean on our climate.  Second, it means that our average annual low temperature has risen.  Finally, it means that we are now in an area where less cold-hardy plants can overwinter without dying. 

It's always good to remember that climate refers to long term patterns in weather.  Last winter, we were buried under feet-worth of snow and freezing.  This winter, our temperatures are running above normal and there have only been two snowfalls of note (and by "of note" I refer to inches, not feet).

If you would like to look up your new hardiness zone, please use the tool on this blog!