8

The USDA just released the first new hardiness zone maps since 1990. Am I still in the same zone?

Ed Staub
  • 6,389
  • 25
  • 31

1 Answers1

7

High-resolution state maps are available here.

In New Hampshire, most areas are now around a quarter-zone warmer, moving a lot of the state from 5a to 5b. The eastern half of Massachusetts, and southern Mass west to Springfield, went from mostly 5b to a 6a or 6b.

For the moment, at least, you can find old maps, for comparison, here. They'll probably update them soon, though.

Ed Staub
  • 6,389
  • 25
  • 31
  • +1 just for that link, I hadn't seen that interactive map site before. Keep in mind when you're looking at the maps that they are *not* really as precise as they seem to be. If you have interesting geography in your area, the climate in your backyard may be different than what the map shows. E.g. the frost map on that site shows me with first frost around Oct 1st, but my tomatoes beg to differ. – bstpierre Jan 26 '12 at 19:13
  • Looks like we (DFW) haven't changed zone, but there is also the question of what is normal and what is extreme. The definition of 8a (our designation) matches last winter - but that was a particularly cold winter for us. I think 8b/9a is probably more representative of a normal winter. – winwaed Jan 26 '12 at 20:47
  • @bstpierre FWIW, [the new state zone maps](http://planthardiness.ars.usda.gov/PHZMWeb/Maps.aspx) are much more detailed - they're clearly computer-generated from higher-resolution data, whereas the old ones were hand-drawn. There are some surprising hot- and cold-spots. – Ed Staub Jan 26 '12 at 21:33
  • @winwaed Look carefully at a hi-res state map, and I think you'll find that Irving (or at least part of it) is shown as 8b - illustrating the hot-spots I noted above. – Ed Staub Jan 26 '12 at 21:43
  • Yes I was looking at the national map. We have a definite heat island around the DFW Metroplex, but interestingly the zone hotspot you point to, looks to be defined by the Trinity River area - probably more sheltered. – winwaed Jan 26 '12 at 21:47