What are the criteria for "Zones"?

From: "Ron Iles" roniles at eircom.net> on 2002.05.21 at 23:44:50(8840) Please can someone explain what criteria are used for "Zones"? With a range of rarely freezing to rarely touching 80F, what "Zone" is West Cork Ireland? This is 20F too low in summer & 30-40F too low in winter for growing Spaths outside, especially with sea winds etc. +More Ron

From: "Hawaii Tropical Botanical Garden" htbg at ilhawaii.net> on 2002.05.22 at 02:46:58(8841) Hi Ron, Climate zones are also called hardiness zones and generally refer to the degree of cold, without much reference to degree of warmth. Frustrating for those of us in warmer climes, there is very little information on cold REQUIREMENT of plants. For example, it seems you are in USDA Climate Zone 9, which is comparable to San Francisco, California. You would be highly successful with fuchsia, bulbous begonia, etc. However, here in Hilo, Hawaii where the lowest temperature year-round rarely hits 60 F, (15.6 C.), we cannot grow these beauties and there is little horticultural information on this so we try and fail... however, with some things we do succeed. I am growing a fine example of the Alaskan Cedar (Chamaecyparis nootkatensis f. pendula) with no problem at all! Check this website: www.aroid.org/horticulture/zonemap/europe.html +More With all best wishes, Scott ----- Original Message ----- To: Multiple recipients of list AROID-L Sent: Tuesday, May 21, 2002 1:44 PM Subject: What are the criteria for "Zones"? Please can someone explain what criteria are used for "Zones"? With a range of rarely freezing to rarely touching 80F, what "Zone" is West Cork Ireland? This is 20F too low in summer & 30-40F too low in winter for growing Spaths outside, especially with sea winds etc. Ron

From: "George R Stilwell, Jr." grsjr at juno.com> on 2002.05.22 at 03:50:47(8843) 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 +More 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/.

From: "Marge Talt" mtalt at hort.net> on 2002.05.22 at 04:55:50(8845) Ron, The US is so vast with so many different climates that the zone system was developed using the average low temperature - not exactly pertinent because our zone 8 covers climates that are extremely dissimilar...but, it's a start. The American Horticultural Society has recently developed a heat zone chart along similar lines but for heat tolerance. It is marginally useful since most plants have not been rated for it and it does not take into consideration many climate factors. +More UK, including Ireland, is generally similar to our zones 7, 8 and 9 - but more those zones on the west coast, not our east coast, where we have very high summer temperatures and humidity - and hot, humid nights, which many plants do not like at all. Here's a map showing USDA zones for Europe: http://www.marblenet.es/pjse/mapuse.htm and, here's another: http://www2.dicom.se/fuchsias/eurozoner.html This site has information about US hardiness zones and the temperatures for each in F and C. http://markw.com/hzones.htm Marge Talt, zone 7 Maryland mtalt@hort.net Editor: Gardening in Shade ----------------------------------------------- Current Article: Online Nurseries 2002 - Garden Vision http://www.suite101.com/welcome.cfm/shade_gardening ------------------------------------------------ Complete Index of Articles by Category and Date http://mtalt.hort.net/article-index.html ------------------------------------------------ All Suite101.com garden topics : http://www.suite101.com/topics.cfm/635 ---------- Please can someone explain what criteria are used for "Zones"? With a range of rarely freezing to rarely touching 80F, what "Zone" is West Cork Ireland? This is 20F too low in summer & 30-40F too low in winter for growing Spaths outside, especially with sea winds etc. Ron

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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