In the opposite direction, there are a number of succulents, purportedly some using Crassulacean Acid Metabolism-requiring a temperature drop at night- which simply will not survive in high night temperature areas. No problem with that here, where single digit C temperatures (i.e. below 50F) are common even in mid-summer, but that means I don't even consider moving tender cacti and succulents or other plants outside for the summer..
I should add that while we have cool nights, we also have at least medium humidity levels most of the time, and copious dew through most of the year that is above freezing..... It remains to be seen what effect these conditions will have on most plants, not many folks in my area (that I have heard of, at least) growing many of the things I hope to try! I think providing a long enough, hot enough summer for some of the American West drylanders may be a challenge.. Cohan West Central Alberta, Canada, Zone 2-3 record temps from 10-20 miles away: min -45C/-49F;max 34C/93F http://picasaweb.google.com/cactuscactus On Sat, Jan 15, 2011 at 5:49 PM, Jane McGary <[email protected]>wrote: > The effect of summer humidity, or lack thereof, on night cooling is often > discussed by gardeners in the western United States. One person suggested > that plants that had evolved in regions with high summer humidity and heat > might be adversely affected by the night cooling that occurs in dry summers. > In my previous garden at 1600 feet elevation east of Portland, Oregon, the > night temperature drop in midsummer could be as much as 40 degrees > Fahrenheit. It will probably be less in my new garden because it's closer to > the city and lower elevation (about 500 feet), so it may be affected by the > urban heat island factor. It was speculated in one conversation that plants > that have evolved with dry, cool nights simply "metabolize themselves to > death" in humid regions, while those from summer-humid regions are "shocked" > into near-dormancy by cold summer nights. > > Obviously, not all plants from Japan or South Carolina will die in the > Pacific Northwest; we can grow perfectly decent hostas if we want to. But > there are a number of plants that simply fade away over the course of two or > three years here, while on the Atlantic Coast they make huge, floriferous > specimens. > > Jane McGary > Portland, Oregon, USA > > > > > _______________________________________________ > --
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