The USDA plant hardiness map is a gardener's best friend. All plants are rated for their zone hardiness and the Hardiness Zone map is broken into regions based on the average winter temperature (low). But that's all changed.
For the first time in 25 years, the US Department of Agriculture has released a new map. Check out NJ below.
This reflects what most gardeners and growers already knew and what 2011 has made abundantly clear, our winters are warmer. They can chatter on about whether or not climate change is real but the plants don't lie.
For the Garden geek in you:
Most of the continental US shifted a half a zone higher. The 2012 map is based on data from 1976-2005 and gathered from a whopping 8,000 climate stations. The previous map only tracked 13 years of data. If you have suffered with the reading of the old map, you'll be happy to know that the new map has been issued as an interactive GIS (Global Information System) so you can zoom in on a particular area and/or plug in your zip code. Due to technological advances, a great deal more info. was taken into consideration like elevation and topography. Notably, the previous map divided the US into 11 zones and it has now been expanded to 13. Hawaii & the Puerto Rico are now included as well.
This shift is good news for the New Jersey Wine industry, we've been classified as a viticulture zone. Kinda cool.
No map will ever eliminate the potential for weather surprises. You may feel inspired to incorporate different plants in your garden, providing extra winter protection but it's still a gamble. Consider yourself warned :)
If you have any questions about the map, you should call the Purdue Extension Service at 812-435-5287.