![The United States Department of Agriculture has reworked the Plant Hardiness Zone Map for the first time since 1990. For over two decades gardeners and farmers have used this regional map to determine which plants will successfully grow in their region and when to sow (and the government, in turn, to determine crop insurance risk, etc.).
The revised map, developed by the USDA’s Agricultural Research Service and Oregon State University’s PRISM Climate Group is for the first time interactive (albeit it, mildly) in that users can isolate a state or search by zip code. That’s a step in the right direction.
But the most interesting change may be the shift in growing zones:
“Compared to the 1990 version, zone boundaries in this edition of the map have shifted in many areas. The new map is generally one 5-degree Fahrenheit half-zone warmer than the previous map throughout much of the United States. This is mostly a result of using temperature data from a longer [now 30-year versus previous 13-year records] and more recent time period […]” but also more sophisticated measurement systems. - USDA Press Release
Noteworthy in this press release is the absence of any mention of rising temperatures as a possible cause for these growing region shifts, and an explicit reference to the fact that some of the zones have gotten cooler, as if to silence global warming alarms before they sound.](http://25.media.tumblr.com/tumblr_lys31uHscJ1qz5h5go1_1280.jpg)
The United States Department of Agriculture has reworked the Plant Hardiness Zone Map for the first time since 1990. For over two decades gardeners and farmers have used this regional map to determine which plants will successfully grow in their region and when to sow (and the government, in turn, to determine crop insurance risk, etc.).
The revised map, developed by the USDA’s Agricultural Research Service and Oregon State University’s PRISM Climate Group is for the first time interactive (albeit it, mildly) in that users can isolate a state or search by zip code. That’s a step in the right direction.
But the most interesting change may be the shift in growing zones:
“Compared to the 1990 version, zone boundaries in this edition of the map have shifted in many areas. The new map is generally one 5-degree Fahrenheit half-zone warmer than the previous map throughout much of the United States. This is mostly a result of using temperature data from a longer [now 30-year versus previous 13-year records] and more recent time period […]” but also more sophisticated measurement systems. - USDA Press Release
Noteworthy in this press release is the absence of any mention of rising temperatures as a possible cause for these growing region shifts, and an explicit reference to the fact that some of the zones have gotten cooler, as if to silence global warming alarms before they sound.
