Microclimate aside...are new Zone maps better?

Discussion in 'HortForum' started by kia796, Feb 18, 2007.

  1. kia796

    kia796 Active Member

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    I'm no closer than before to finding my zone.
    While I'm certain a lot of work has gone into this project, is your "new zone" more accurate than previous maps?
    http://www.glfc.cfs.nrcan.gc.ca/landscape/ph_tech_details_e.html

    Is the UBC BG active in this project?
    It's great that public input is encouraged. Rather a novel approach for government.
     
  2. LPN

    LPN Well-Known Member 10 Years

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    That zone map is a disaster! It has greater Vancouver and Victoria listed as zone 6 -10f to 0f (-23c to -18c) !!! Some detail has been left out ... no indications for Gabriola, Denman or Hornbey Islands. Town names are wrong etc.
    Don't put too much emphasis on "zones" because they really don't tell the whole story. I live in an area which is largely zone 8b Vancouver Island and it's certainly a whole lot different than zone 8 in Texas.
    Biogeoclimactic sub-zones are better indicators as to overall climate and plant performance.

    Cheers, LPN.
     

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  3. kia796

    kia796 Active Member

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    Apart from those glaring errors, perhaps the project is still in its infancy.
    I long ago stopped looking at the US maps and had hoped the updated Canadian version would provide more answers than questions.

    I'm optimistic that public input of species will provide some useful reference, assuming the project is getting good response.

    I'll search biogeoclimatic sub-zones and see where I end up. I'm frankly fed up guessing which zone I'm in. It was trial and error (mostly error) that started with a move from Vancouver, buying a Eucalyptus, then watching it die that winter despite a snug spot near the house. And so on it went every year with various plants, most of which are now "residing" at the landfill.

    Thanks for the word of caution LPN.
     
  4. hortfreak

    hortfreak Active Member Maple Society

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    Zone maps are not intended to be the definitive answer to whether or not a plant will survive in your particular area. They are only intended to be a guide. The program the government is currently engaged in (tracking what survives and what blooms when) should be a better indicator for gardeners but will still only be a guide. You have to appreciate that even within the confines of a single property there can be great variation. My former garden was certainly proof of that. I had a 3-zone differential within a very small garden.
     
  5. kia796

    kia796 Active Member

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    I agree zone maps are a guide only. But thought that by now there'd be something "out there" a little more definitive than the broad-brush used in the past. I've googled bio-geoclimatic zones and confirmed what I already knew: interior douglas fir (dry) zone. Now looking for regions within that zone, and found nothing on Google. Will try the local Ag Dept office to see if they have updated maps for my region.

    Despite the guide caution, I'm looking forward to seeing the public input of the government program.
     
  6. kia796

    kia796 Active Member

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  7. hortfreak

    hortfreak Active Member Maple Society

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    I think the new guide based on gardeners input should be very helpful. This, of course, will reflect individual requirements such as dryness, snow cover, etc. The weather has been so crazy for the last couple of years that I am not sure even this will really help in an "unusual" year. I am very much looking forward to seeing the results of this study. I can't remember how much longer it has to run. Then, of course, a report will have to be prepared.
     
  8. kia796

    kia796 Active Member

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    ]"The weather has been so crazy for the last couple of years"[/I
    That's why I'm so interested in this project and secretly (*grin*) hoping my little spot in paradise can push the constraints of old zoning.

    We all have examples of how weather has changed, in particular milder winters. In the Okanagan, we're seeing more rain in spring and fall...a real benefit on our hot dry southslope. This, when combined with a constructed micro-climate--such as a residence with a wing that shelters from northwest winter winds, and additional makeshift protection--such as a 6ml plastic cover on a frame, can really push a zone.

    Naturally I'm looking at this all with a very narrow human lifespan view, barely a blip in nature's scheme of things. For me, it's the silver lining in the dark cloud of climate change.
     
  9. hortfreak

    hortfreak Active Member Maple Society

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    Ah, yes, the upside to all of this. You are right, it is a "silver lining in the dark cloud of climate change". I think perhaps this may make the zone maps even less useful, although we could just adjust the zone of our particular little bit of paradise warmer by one zone. I suspect that at some point the zone maps may go the way of many other things---in the trash bin.

    When I first started gardening many years ago, I did not know anything about zones, or what would survive, or much of anything else. I just went for everything I liked. Surprisingly, most everything survived. Some of these plants were (and still are) zoned for a climate much warmer than where I lived at the time.
     
  10. kia796

    kia796 Active Member

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    "...warmer by one zone". The exciting opportunities that would give us!
    "just went for everything I liked. Surprisingly, most everything survived." That was very lucky indeed.

    My nemesis...I figure if a local nursery is carrying something, I should try it! Then 20 yrs later when the palm, for instance, gets too heavy and big to haul in and out of the house, I find myself wishing I could plant it outdoors, hence the "zone pushing" wish.

    I've heard of folks planning to build a new home, the exterior design based almost entirely on numerous angles and "els" because of the microclimate opportunities that they allow. We gardeners can be a crazy lot!
     
  11. abgardeneer

    abgardeneer Active Member

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    With respect to microclimates and significant zone differences within the same yard, my experience has been that the actual hardiness of many plant species has not been well tested. (Note that all of my comments relate to the cold-zone end of the range, not to planting palms in Vancouver or to pushing one's luck with semi-tropical species.) When we in colder zones think we are "pushing the zone", I believe often all we are doing is proving that such-and-such a plant really is hardy in zone 3 (or wherever), despite that the plant tag and the literature (the vast majority of which originates from much warmer zones) claim it's a zone 5 plant.
     
  12. kia796

    kia796 Active Member

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    You've made an excellent point, abgardeneer. Thank you. If there's tolerance for a little mirth...I look at all my house-bound tropicals and sub-tropicals, and my wish is to wake up one morning in Zone 10, without having travelled.
     
  13. hortfreak

    hortfreak Active Member Maple Society

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    It is a good point about the untested zone hardiness of plants. Too many assumptions are made, and there are too many environmental variations within a given area. However, my former garden truly did have a 3-zone difference. I could grow very surprising things in a small well protected area but could not grow things in a very open place that should have been bone hardy. I think wind plays a much larger factor than most people think. I have certainly found that to be the case here in Prince Edward County. Even with snow cover, the windy garden around my patio seems to have trouble supporting much of anything very successfully. It is a very exposed area. On the other side of the house, which does get some wind but far less and not as strong as on the other side, I do not have nearly the problem of over-wintering plants.

    These zonal differences have been noted by many of my friends with gardens that vary greatly in environmental conditions. The varying conditions may be created by us by virtue of design, but they are nevertheless existent. I know someone in Toronto that has grown a banana tree outdoors for many years. I know many people who have tried and gotten nowhere. I know people that have been able to successfully grow camellias outdoors where others cannot, even in the same neighbourhood. So, how do zone charts help us with these variations? Generally, if I decide to grow a plant that is of questionable hardiness or even supposedly completely outside my zone, I research that plant and its native conditions and then try to match those conditions. I have found this to be a very reliable way to determine whether or not a plant will survive. Not 100% reliable, of course, but it gives me a really good shot at growing things I might not otherwise have tried.
     
  14. LPN

    LPN Well-Known Member 10 Years

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    FYI ... your "banana tree" comment needs correcting. Bananas don't grow on trees, they emerge from pseudostems. Yes, I know I'm picky at times. hahah!

    Cheers, LPN.
     
  15. hortfreak

    hortfreak Active Member Maple Society

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    Thank you, LPN. We so often say things that aren't quite correct without thinking. I just got mine back for all the times I correct people for their use of "variety" and "family". Cheers.
     
  16. LPN

    LPN Well-Known Member 10 Years

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    I never quite know how people will react to these suggestions and so I rarely (on forums anyway) correct people. People can and have gotten defensive and nasty comments may arise. So when I do correct, I have to be carefull with my wording.

    While we're on the topic, another one that bothers me is some peoples use of the word 'Foliage'. I hear "foil -ee-age" rather than "fol-ee-age", so maybe there's some french language inflection that somehow got past along.

    Cheers, LPN.
     
  17. abgardeneer

    abgardeneer Active Member

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    Well, I think a way (the only way, perhaps?) to separate the effect of conditions (i.e. soil properties, sun/shade, moisture, wind, etc.) from cold hardiness is to look at the individual species being wintered successfully in various areas. There is an effort underway to collect this sort of data (and I'm not sure if this is the "participation" in climatic zone determination that was referred to earlier?), and if more gardeners would contribute their hardiness records to this study, perhaps more of the "mysteries" of zones and plant hardiness could be figured out. (If I recall correctly, the intent of the government study is to actually to define climatic zones using plant hardiness, but IMO, given that plant hardiness is poorly understood, it seems to me that the more likely outcome would be a better understanding of actual plant zone ratings!) Anyway, here is the website for "Going Beyond the Zones":
    http://www.planthardiness.gc.ca/

    To me, of course, the value of collecting such data depends on the participation of the more adventurous gardeners across the country. [If the only people who participate are those who only attempt to grow species that "fit" their zone (i.e. "I'm in zone 5, therefore I will not attempt any plant rated at warmer than zone 5"), according to the published, possibly erroneous zone ratings, then the outcome could be just a false reinforcement of those original incorrect zone ratings! And would also lead to erroneous conclusions on climate ranges or change...] Anyway, that's as lucid as I can make my thoughts on this right now, LOL!

    I agree 100% on researching the conditions that occur within the native range of a plant, as a very pertinent first step to establishing its zone rating. I see, ad infinitum, that untested zone ratings are simply repeated from publication to publication. For example, I've seen Agastache foeniculum rated as zone 6(!) in various publications, which totally ignores the fact that the species is native across the Canadian prairies through zones 1 and 2! The other thing I take from this is that very few gardening books rely on actual research or experience, and that, unfortunately, a great many simply copy previous publications.
     
  18. LPN

    LPN Well-Known Member 10 Years

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    For many of us in the milder regions in the PNW of BC, we don't refer to any of the Canadian info because it dosen't apply. Info from around the Puget Sound and the San Juan Islands is more benefical.

    Cheers, LPN.
     
  19. kia796

    kia796 Active Member

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    Well, LPN, your input would be most valuable to the Canadian study.

    abgardeneer, I've spent a lot of time poring over those maps, and despite my 3 attempts to get the co-ordinates "bang on", the 3 results were "zone 4b, zone 5a, zone 6a".

    Where is that emoticon for wasted time? (&^*%$$#) yup, that's it.
     
  20. abgardeneer

    abgardeneer Active Member

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    Well, no offence, but just to clarify, I'm wasn't really expressing an opinion on the accuracy nor on the user-friendliness of the current zone map in your area or anywhere else (though due to the relatively flat topography in our area, it's pretty straightforward here)... I'm just stating that, as a gardener, I'd find it really interesting to be able to use the gardening data collected, to see what grows where (to put it in the clearest terms), LOL!
     
  21. kia796

    kia796 Active Member

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    I agree with you completely. A zone map is simply another tool we gardeners wish to use, in conjunction with what we already know about our property -- soil composition and pH (for example many Okanagan soils are boron deficient), aspect (on south slopes, spring can appear to arrive sooner than on a northern slope, not necessarily a good thing), all that stuff.

    Many of us have "an eye" on a particular tree or shrub we'd like to plant (in my case a Daphne), but are leery to try it because zone maps show us to be several zones away from what the plant "prefers". So then we find ourselves looking for a microclimate around our homes, areas that are sheltered from cold northwest winds for example, and use that information to "push a zone".

    Generally about five years later, I'm humiliated by nature's reminder of where I live.

    Assuming enough input is received from the public (didn't see any deadline for submissions), compiled data would be most interesting. Just a guess...but presume global warming and inaccurate zone maps under the old system are triggers for this study. Or maybe it's because the technology now exists to fine-tune zones...or a make-work project for the surplus of bureaucrats in Canada? Whatever the reason, gov't needs to promote this project in areas other than a seldom-viewed website to garner public attention.

    abgardeneer, is it starting to feel like the end of winter in your area? Here, robins have returned.
     
  22. Weekend Gardener

    Weekend Gardener Active Member 10 Years

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    I agree. The Canadian "plant survival" zone map is completely out of touch with what I know and have experienced in South Western BC over the last 20 odd years of gardening. We are, in Coquitlam (Zone 8a, according to the map), should be one zone colder, not warmer than Delta (6b!) or Vancouver (7a or 7b?) or Vancouver Island (7a/7b)! Granted, it takes into account more than just temperatures - it's equation takes into account minimum winter temperatures, length of the frost-free period, summer rainfall, summer maximum temperatures, snow cover, January rainfall, maximum wind speed and elevation. But it still doesn't jive with the fact that I can't leave canna tubers in the ground, whereas my collegues in Tsawwassen proudly proclaims that they don't have to dig theirs up every fall.

    I think the map's methodology is it's own enemy. It's multifactorial nature and complexity, ironically, renders it useless for what I need.

    Interestingly, it does not seem to make much difference in Zone number if I use the USDA Cold Hardiness Zone rating - our local yearly minimum temperature will put our little nick of the woods at 8a.
     
  23. hortfreak

    hortfreak Active Member Maple Society

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    It is my understanding that the study being done by the government (of Canada) is in response to criticism of the zone maps and in recognition of the difficulties posed by them. It was felt that individual plant species information is more useful. To my way of thinking this is quite so. A plant may be able to withstand temperatures of down to whatever but not if there isn't any snow cover, whereas another plant might. It will take into account all the variable conditions, the tolerance of which will vary from plant to plant. I am not sure just how finite it will be as to regions. I really think the individual plant information will be a very valuable asset to all of us in Canada.

    My recollection is that the program is to run for 3 years or so. I could be wrong on that. It might very well be an on-going study. It has been in place for a few years now. I can't remember when it started.
     
  24. kia796

    kia796 Active Member

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    "the individual plant information will be a very valuable asset to all of us in Canada."
    That's the part that interests me most.
    Yet can you just imagine the download time on THAT pdf?
    Rural areas would have a plugged pipe.
     
  25. hortfreak

    hortfreak Active Member Maple Society

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    Yes, download time would be unbearable for people like me who are stuck with dial-up (at least for the next little while). Hopefully the publication price won't be astronomical or we will be able to download only the parts that are applicable to us.
     

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