I am trying to determine which one of BCs interior valleys has the most suitable climate for a solar hobby greenhouse, but Canadas Plant Hardiness Zones Map (the new 2000 version) is puzzling me. It shows the Okanagan (lake is 345m) as mostly 6a with 6b in some spots, yet the almost 100 meter higher Arrow (lake is 420m) and the yet another 100 meter higher Kootenay (lake is 530m) both as mostly 6b with some 6a along the edges and at the ends. As far as I know, every 100 meter elevation above sea level represents a difference of about 1 degree C, thus the Okanagan should be the warmest. Is there someone here that could explain the reasons for this, or knows where I may get that information? Martin
Other factors such as valleys protected by surrounding hills, creating a local microclimate may be responsible, but you should never consider the zone info. to be the last word in any case. The maps may not be wrong, but so many other factors matter, and zone 5 (or 7 or 10) in one location may have very different growing conditions than another zone 5 area - all the zones do is give a general 'lowest average temp' and nothing else.
Thanks Rima, your comments appear to agree with the much greener/lasher tree vegetation in those two higher Kootenay valleys. Does anyone here know of a plant that requires more winter sun than most others, so that its locations could be used as an indicator of where the most winter sunshine occurs?
I would track your sun pathe throughout the winter, solar insolation varies with the lands' slope, shade interference, and ambient temperature, though I am no scientist, plantings that require full sun in the growing season , may only require adequate protection in the winter, or just the other extreme...protection all winter... What are you intending to create?
I would think for a solar hobby greenhouse, hardiness zone maps would be less than useful. Wouldn't hours of sunshine be a more accurate measure? Canadian National Climate and Data Archive -> Canadian Climate Normals -> Province British Columbia -> Select a weather station. (ideally one with a *)
Thanks K Baron, I am not that far yet. I am currently looking for the best possible location in southern BC to settle (move to from Montreal) and build a combination hobby greenhouse/solar heated house. Thanks Daniel, I have downloaded all the information I could find on that web site, but the majority of stations do not record sunshine hours. Thus, there are not only very many areas in southern BC where absolutely no sunshine info is available, but due to the rather mountainess terrain, local micro-climates do vary considerably. So knowing a plant that requires more winter-sunshine could help me in finding the best location for a solar heated greenhouse. PS: (The info I accumulated over the past year can be seen at http://realgsd.ca/climate/) Martin
Well, we'd really be talking about something with crop (fruit) production, because I can't think of any native plants in the area that require winter sun. In that case, my suggestion would be to contact the Ag Canada research program in Summerland to talk with someone who has first hand experience. Many of the scientists do work in both the Okanagan and Kootenays, e.g. Scott Smith.
Actually, I have been using peach trees as an indicator of plant hardiness zone 6b, as I know that they do not grow in 6a, at least not in the Niagara region of Ontario, mostly due to being divided by the Niagara escarpment. Thanks Daniel for the lead on the Summerland research station. That is real promising.
Please note that B.C. has so many micro climates...you will be surprised how varied one valley in the Kootenays varies from the next...
Hi I realise this is probably an out of date reply now ,but we are also looking for the highest sunshine hour areas in BC and aren't having any luck at all. How did you make out?
There are a few areas to consider, Lilloet, Oak Bay, Clinton, Oliver,(Oyama) Ladner and The Southern Gulf Islands.... Cheers, and good luck!
I would expect that total annual precipitation would correlate pretty closely with winter sunshine in BC. You can try the Atlas of Canada precipitation map at http://atlas.nrcan.gc.ca/site/english/maps/environment/climate/precipitation/precip for this. It should give you a rough guide to sunshine.
An interesting source of weather information for Southern Vancouver Island is the UVIC School-based Weather Station Network: http://www.victoriaweather.ca/ The participating schools record lots of information - including UV index - which relates to the sunshine. If you look at a number of stations, you will see that there are many microclimates in that fairly small region. As an aside...I have sat in a park in Oak Bay watching my grandson play. Above the sky was overcast. To the east and west were horrid black clouds, and it was probably raining there. My son once brought me up to Mount Douglas, where you can actually see the incoming weather split off to the east and west, leaving Oak Bay and Victoria in the clear. Cindy
