New hardiness zone map
The Arbor Day Foundation has released a new Hardiness Zone map that takes shifting climate trends into account. This was the reason that the USDA updated its well-known zone map in 1990, and Arbor Day felt it was called for again.
The new Zone Map uses zone designations that match the traditional scheme used by the USDA, and therefore looks pretty familiar. For instance, Zone 6 is still the region that experiences annual lows in the 0 to -10 degree F. range. However, due to somewhat warmer winter temperatures during the past decade, the zones have shifted slightly northward.
To access the Zone Map, go to www.arborday.org.