The person who criticized my posts for being too complicated, better just stop now. I guess it helps to remember the zones are 'USDA', which is the US department of agriculture and really has nothing to do with ornamental plants. Nein. Ornamental plants ARE part of the USDA's mission. That's why the National Arboretum is under their aegis. Remember wholesale nurseries definitely are a form of agriculture. The USDA zone system gives the barest measure of whether a plant can survive in a given area. Obviously, something hardy only in zone 10 cannot survive in zone 6. Beyond that, there are many other factors. The latest revised USDA zone map seems very accurate to me. I know of gardens along the Delaware river in NJ that really do seem like zn 7b. But it took a ridiculously long time to come out...considering the overall crunching of data probably took a few hours on a high perf. workstation or server. (in case you don't know, it's based on a climate model developed at U Oregon called "Prism") This was not some advanced climate simulation going on like trying to predict hurricanes. And given that computer technology has advanced so much including the algorithm development one would have to say the current USDA map reflects a certain lack of vision, though, again, at least they finally got it correct. By this I mean something like the Sunset system could have been developed, although there were problems with that approach if you try to extend it over the country. Rather than discrete numbers that could get ridiculously long for certain plants (i.e., this grows in 21, 33,34,35,36,37,38,40,52,61,62,63,64,75,78 etc) it could have used a series of vectors that graph a space representing the plant's preferences. Zones 1 to 10 would still be the first dimension of this system so you don't "break compatibility" with what we already have. The two main additional factors I would propose would be aridity, and summer temperature. There are several reasons for this; namely, there are already 2 factors certain nurseries use when selling plants. The AHS "heat zone" map exists, and is used by a few nurseries to show warning on certain species, and aridity scales have been adopted by Desert Northwest and High Country Gardens. Mind you these scales would not necessarily be linear and could code a sub-dimension, or even be matrixed to code an additional factor. For example it might make more sense for moisture to go: part of year arid - sporadic/none of year - all year - part of year but high atmospheric moisture. Because there are non-linearities in the way plants behave with respect to that, and with summer temperature. Some cool summer seasonal plants are actually known to grow in all year rainfall climates like England, but only with cool summers. The point is the arrange things in the way that leads to the most chances of solid groupings. Such mathematical shenanigans might make it hard for people to understand how to derive their own zone, but the point is it doesn't matter. They will get their zone off a map. Also different from the Sunset zones, there no need for a comprehensive, singular map because everyone will use some kind of smart device in the future that can easily click one location between 3 or more different maps. So a zone like mine would go from 7a (I think the a/b is of more limited usefulness than most people realize, though I have and will continue to reference the subzones) to something like 7J6. 7 being 0 to 10f min annual temp, J being a climate with rain all year but some expectation of brief droughts, and 6 being heat zone 6. Let's call it the Comprehensive Plant Zone. A _PLANT_ ranges, versus a gardening location, would go from "USDA zone 7-10" for a maritime climate plant like Eucryphia, to "CPZ (comprehensive plant zoning) zone "7H2-10M4" meaning that range of minimum winter temps, and a generally moist climate though accepting somewhat dry summers, as long as 3) the summers are cool. I would instantly recognize that I can't grow the plant because I'm off on one of the codes. Of course, this will never happen and there will be howls of "it's too complicated" but you can be sure in the early 1960s some hayseeds saw the first Harvard zone map and said "oh them fancy professors and their durn maps, I know what grows here and uh don't need some map." Also let's face that other than the big midwestern cities the net migration in the country is towards the SE, S & W where the USDA zone system is least useful. USDA system is most useful for telling people in Iowa there are many, many plants that they are far too cold to grow (sorry Iowans, someone had to be an example) than answering the question for someone in Phoenix, Arizona of whether a certain species of Protea could grow there. (and I reckon a couple of the most heat tolerant ones could) That a sunset zone map was made for the whole country is something I applaud, my idea just tries to make their system easier to use when dealing with a lot of customers and plants. Instead of saying "that only grows in 31, not 42" it's more helpful to say "your moisture factor of J is too much for an A-E plant, it will rot".

Haahahahaa! Karen this is SO funny. I'm bursting into laughter reading these posts again, and remembering writing and reading them at the time. Well done! And my favourite part about Martha Stewart dropping in with her dish towel parachute!!! WAY too funny!

Thanks for all your hard work Karen! Can't wait to read it in its entirety. Jodi-

Very appropriate at any time of the year, but particularly at the dawning of the new year ahead. Thanks muchly.