This is a project to survey cold hardiness and heat tolerance by assembling lists of plants which survive growing outdoors in the ground year-round for multiple years.
Hardiness is the ability of a plant to survive growing outdoors, in the ground. There are two forms of hardiness that are of interest to most of us -- Cold Hardiness and Heat Tolerance.
This is the ability of a plant to survive frost or freezing temperatures. There are limits to the extent of cold hardiness in all plants, but a rough estimate of their cold hardiness can be made from the climate characteristics of their natural habitats. In the U.S.A., we commonly use the USDA cold hardiness zones, which are estimated based on the average lowest winter temperatures of a locality.
The ability of a plant to survive high environmental temperatures is the "heat tolerance." There are no widely used standards for judging heat tolerance, but the American Horticultural Society has recently issued a map showing "heat zones" for the U.S.A.
If you grow any bulbs in the ground and have them survive for more than 12 months -- preferably for more than 24 months -- I would like to have you contribute to the database. The data need to come to me in electronic format, and you can download template files from this site.
Contact me by e-mail at jim@shieldsgardens.com
Visit the Great Lakes Bulb Society home page.
For more information about the Great Lakes Bulb Society, contact:
For information about this account, contact:
James E. Shields, jim@shieldsgardens.com
Last updated on 5 June 2001.
© Copyright 2001 by James E. Shields. All rights reserved.