On 19 Feb 2003 21:56:40 GMT, (Nick Maclaren)
wrote:

Even then, they don't match. The conditions are just too dissimilar.
And the USDA zones are a damn-fool idea anyway, as they measure an
extreme value rather than a central one, and that is NOT a reliable
indicator of what will affect plants. If they measured the average
minimum daily average, they would translate a LOT better.


Now, now, Nick, temper, temper. The USDA zones were devised with
a specific purpose in mind, hardiness of *woody* material in the
continental USA. The USDA has had some pretty bright people
toiling away in the bowels of its bureaucracy (at least in the
past), and I am quite sure that the hardiness zone system was not
just a bright but ill thought-out idea someone foisted onto the
world in a moment of carelessness.

That the system has been widely misapplied to other types of
plant material and in other places is not an inherent fault.


--
Rodger Whitlock
Victoria, British Columbia, Canada