The new 2012 USDA Hardiness Zone Map shows average minimum temperatures for areas just like the prior maps. However, it also incorporates a few changes that are designed to make landscapers, gardeners, and farmers very happy. On the United States Department of Agriculture's website, you are able to print or to download a map of the state, region, or entire United States that has the hardiness zones color-coordinated on it. There are many different sizes and resolutions, depending on your preferences and needs.
New Changes for the 2012 Map over the 1990 Map
Other than some more precise measurements of the zones, they have taken into account the variations of water temperature and elevation changes. Many areas had their zone numbers change, like zone numbers rising in the northern United States and some areas of California seeing lower numbered zones. On the USDA website, gardeners and farmers can go and put in their zip code and get a customized hardiness zone map designed for their area. The map is now interactive and uses a GIS-based map. This interactive map means more customization and ease of use for the average user.
Zone Differences
There are both temperature differences and new creations of zones between the old 1990 map and the new 2012 hardiness map. Zone differences include:
- Zone 1 went from -50 degrees F with no sections to -60 degrees F to -55 degrees F for section "A" and -55 degrees F to -50 degrees F for section "B".
- Zone 2 stayed from -45 degrees F to -50 degrees F for section "A" and -40 degrees to -45 degrees F for section "B" to
- Zone 3 stayed from -35 degrees F to -40 degrees F for section "A" and -30 degrees to -35 degrees F for section "B" to
- Zone 4 stayed from -25 degrees F to -30 degrees F for section "A" and -20 degrees to -25 degrees F for section "B" to
- Zone 5 stayed from -15 degrees F to -20 degrees F for section "A" and -20 degrees to -25 degrees F for section "B" to
- Zone 6 stayed from -5 degrees F to -10 degrees F for section "A" and -10 degrees to -15 degrees F for section "B" to
- Zone 7 stayed from 0 degrees F to 5 degrees F for section "A" and 5 degrees to 10 degrees F for section "B" to
- Zone 8 stayed from 10 degrees F to 15 degrees F for section "A" and 15 degrees to 20 degrees F for section "B" to
- Zone 9 stayed from 20 degrees F to 25 degrees F for section "A" and 25 degrees to 30 degrees F for section "B".
- Zone 10 stayed from 30 degrees F to 35 degrees F for section "A" and 35 degrees to 40 degrees F for section "B".
- Zone 11 went from 40 degrees F or more with no sections to 40 to 45 degrees F for section "A" and 45 degrees F to 50 degrees F for section "B".
- Zone 12 was not on the old map. Its new temperature range is 50 degrees F to 55 degrees F for section "A" and 55 degrees F to 60 degrees F for section "B".
- Zone 13 was not on the old map. Its new temperature range is 60 degrees F to 65 degrees F for section "A" and 65 degrees F to 70 degrees F for section "B".
The new USDA Hardiness Zone Map shows the effects of global warming and the creation of even warmer climates with the additions of zone 12 and zone 13. While there are subtle changes in the map with more precise shots of water temperatures and elevation temperature changes, the map continues to be one of the gardener's best tools.
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Tina Samuels - Tina Samuels specializes in health, animal, and gardening articles. She authored "A Georgia Native Plant Guide".
