Page 12 | April 14, 2012
Spring Home
Supplement to the Wadena Pioneer Journal
Maps reveal new plant hardiness zones in United Sates
Gardeners rely on a number of factors when decid13 (60-70 degrees F). Each zone is a 10-degree Fahrenheit ing on what to plant in their gardens and around their band, further divided into A and B 5-degree Fahrenheit property. One of the most important things to take into zones. consideration is the climate. A hardiness zone describes a geographically defined Since 1960, the go-to source for climate and relation area in which a specific category of plant life is capable to agriculture has been the U.S. Department of Agriculof growing, as defined by climatic conditions, including ture’s (USDA) Plant Hardiness Zone map. In 1967, Agits ability to withstand the minimum temperatures of the riculture Canada developed their own map that took into zone. Summer temperatures are not factored into the mix. consideration Canadian plant survival data and a wider Therefore, areas with similar winter patterns and average range of climatic variables. The maps remained constant lows may be in the same zone despite having drastically until now. different highs. Hardiness zones may not take into conIn January 2012, the USDA released an updated zone sideration snow cover, either. Snow helps insulate the map. The map is now more precise and reflects microclisoil and hibernating plants. Therefore hardiness zones mates, heat islands, prevailing wind, elevation, and generare more like guidelines instead of foolproof methods of ally better data. It breaks down the country into 13 unique determining viable plants. zones from the previous 11. Individuals who once resided Although a poster-sized version of this map will not be in a particular zone may find that they are now moved into available for purchase from USDA, as in the past, anyone another zone. This updated map has taken into considermay download the map free of charge from the Internet ation climate changes that have occurred between 1976 onto their personal computer and print copies of the map and 2005. You now may be able to try plants that you may Hardiness zone maps courtesy of the USDA as needed. have been skeptical about in the past. When shopping for plants, most will display a hardiThe new map now offers a Geographic Information ness zone right on the container to help you determine included to ensure the map is readily accessible to those who System, orGIS, -based, interactive format and is specifiwhether this particular plant will be acceptable outdoors in cally designed to be Internet-friendly. The map website also lack broadband Internet access. your zone. To learn more about hardiness zones, visit www. The new version of the map includes 13 zones, with the usda.gov or http://planthardiness.gc.ca. incorporates a “find your zone by ZIP code� function. Static images of national, regional and state maps have also been addition for the first time of zones 12 (50-60 degrees F) and