Re: What are the criteria for "Zones"?

From: "Randall M. Story" story at caltech.edu> on 2002.05.22 at 15:03:16(8848) As people have mentioned, the USDA zone concept is really pretty limited. For example the foggiest parts of San Francisco, some of the hotter and drier parts of Southern California as well as Miami Florida are all zone 10!! Yet you certainly can't grow a Coconut Palm in San Francisco (or anywhere in California that I know of), whereas a Dracula orchid that would be very happy in coastal California would quickly fry in Florida. And on and on... +More Even the heat index adds very little--there are parts of Florida and the Arizona desert that have both the same heat and cold indexes, yet obviously humidity, rainfall, temperature extremes, diurnal variation etc. are vastly different. In the Western half of the U.S. there has been a different (and unfortunately much more complicated zone system--24 zones!) devised by Sunset Magazine/Books a number of years ago that takes into account things such as humidity, ocean influence, etc. Many of us out here are familiar with it and it is very, very useful. Recently it has been extended to the rest of the U.S. (and Canada I think) creating yet more zones. I don't imagine they've extended it to Europe, yet I'm sure that the climate of Ireland has much, much more in common with certain parts of coastal Oregon/Washington (Sunset zone 5 maybe?) than it has with the equivalent USDA zone anywhere else of the U.S. Anyway, this is obviously really complicated, however someone has come up with a system that makes sense for the U.S. at least. Oh, and it doesn't strictly depend on any particular Fahrenheit (or Celsius) number--you have to look it up on a map. I imagine that much of Europe could be approximated by one of these zones. I don't know if anyone has tried. see http://www.sunset.com/Sponsors/Garden/sunsetmonrovia_r1/htmlfiles/botwzones. html for maps and descriptions of the zones for the western U.S. I don't know of any maps online for the rest of the country. Randy USDA zone 10/ Sunset zone 21 ---------- >From: "George R Stilwell, Jr." >To: Multiple recipients of list AROID-L >Subject: Re: What are the criteria for "Zones"? >Date: Tue, May 21, 2002, 8:50 PM > > Ron, > > Zones have only to do with the mean low temperature. There is a new index > to do with heat > being dffered by the USDA. To answer your question, go to > > http://www.aroid.org/horticulture/zonemap/europe.html > > It's all self evident in this wonderful page. > > Ray > GRSJr@worldnet.att.net > > > ________________________________________________________________ > GET INTERNET ACCESS FROM JUNO! > Juno offers FREE or PREMIUM Internet access for less! > Join Juno today! For your FREE software, visit: > http://dl.www.juno.com/get/web/. >

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