‘American Forests works to protect, restore and enhance the natural capital of trees and forests.’
American Forests Website is an excellent place to find information on
Until recently, the USDA put out a new Hardiness Zone Map every 15 years. In 2005, a new map was scheduled to be released from 16 years of climate data studied by the American Horticultural Society. The AHS draft was published in The American Gardener's May-June 2003 issue.
The USDA reviewed the map and decided that it would not work, because, among other reasons, it was not based on a long enough time period. Some worry that the USDA rejection of the new map was influenced by the current administration and the politics surrounding global warming. The USDA is working on another update with 30 years of data, but there is as of yet no schedule for its release. The USDA map from 1990 is still the current “official” map
After much demand for a more current map, the National Arbor Day Foundation released their own update, the 2006 Hardiness Zone Map. Similar to the AHS update, and from the same US National Climatic Data, it shows much of the country moving a zone warmer. Their animation of the zone changes from 1990-2006 has quite an impact.
The Good and the Bad
A change in hardiness zone may seem like a good thing, in that we can grow a wider variety of plants, but with the plants we want to grow will come the ones we don’t want. There may be increased problems with invasive pests and weeds. Also, the climate warming is not limited to warmer winters. There is an increased potential for extreme heat. See the AHS Heat Zone Map
Any hardiness zone map should be used as a starting point, with plant decisions based on local experience. Know your local microclimates. Upset customers may result from trying borderline hardy plants that may not make it through the occasional hard winter.
International Greening Rooftops for Sustainable Communities,
Conference, Awards & Trade Show
April 29, 30 and May 1, 2007
Minneapolis, MN
By the Green Roofs for Healthy Cities (GRHC)
and the City of Minneapolis
Green Roof Policies, Programs, Design, Implementation, Research and
Performance
UFind- the Urban Forestry Index: a searchable database of publications, videos, websites, and posters about urban forestry and arboriculture.
Resources for Trees: Benefits, Identification, Selection, Biology, Care and Maintenance, Planting, Preservation and Protection, and much more.
From the USDA Forest Service, University of Minnesota, and TreeLink
Webcast - “An Urban Forest Pilot Project: Mapping & Calculating the Benefits of City Trees”
on Tuesday, March 13 at 1 p.m. CST.
Hosted by the WDNR and USFA
Topics Include
