Plant Zones Shifting as Climate changes

Tomorrow is national Arbor Day, although each state has its own celebration of tree-planting, some coinciding with the national, some varying in accord with planting times. The Arbor Day site will provide you with your state's date, as well as your state tree, in case you don't know what it is.

In something from The Arbor Day Foundation yesterday, I learned an interesting, worrisome, alarming, (take your pick, or all of the above) tidbit, the fact that plant-hardiness zones in this country are shifting, causing The Arbor Day Foundation to draw up its own zone map differing quite a bit from the official USDA map. This morning I have stumbled upon an article in USA Today further explaining this trend and the map controversy that accompanies it. Anyone who gardens to any extent is aware of the USDA's map of hardiness zones. The map we are currently using is 18 years old, drawn up in 1990. In a further illustration of this admin's reluctance to base official statements on anything resembling scientific fact, a new map prepared for the Dept. of Agriculture in 2003 was rejected as showing a warming trend. The USDA hotly denies any hesitation to acknowledge the potential impact of climate change, and says they are bringing out a new map within the year, one reflecting a thirty year period of climate data giving a "fuller picture of the world climate" than the sixteen year period used for the rejected 2003 map. (Emphasis added.)

The article, Warming Shifts Gardeners' Maps, gives us the current USDA map upfront, then provides a place to input your zip code and find your new, warmer, zone using the ADFoundation map. As it's Arbor Day, and Earth Day, and just in general, spring, we're heading to our closest native plant nursery to look at trees that might thrive here in our ever-hotter and drier yard. It's one of the best things we can do right now for our planet. But before you invest in a commitment to a tree, check the Arbor Day Foundation map, the results might surprise you. (Photo: Pinyon Pine, New Mexico's state tree.)

Technorati Tags: Arbor Day, climate change, Earth Day, plant hardiness zones, trees, USDA,