Climate zones

Rodger Whitlock
Fri, 28 Oct 2005 15:54:14 PDT
On 28 Oct 05 at 8:45, John Bryan wrote:

> ...Roger Whitlock's remarks were also to the point, and I
> liked his remarks about being precise and assuming nothing,
> just how far are you Roger from the coast?

Go down my driveway to the street, turn right, and within a 
mile you're at the saltchuck. A ten-minute bicycle ride -- but 
only going there, there's a steep downhill that you'd have to 
walk back up!

That's yet another factor to take into account: altitude. The
Sooke hills west of Victoria get snow regularly in winter down
to, say, the 1000' level (iow on their crests); at the same 
time, here in Victoria proper it's only raining. I think we 
escape regular snowfalls by the skin of our teeth.

Yet another (micro)climatic factor: topography. Those very same 
hills get up to around 2000' altitude or so and catch the 
winter precipitation; we are in a rain shadow, one reason we're 
so dry.

And yet another: katabatics. How well does your property shed 
cold air? I keep telling one hort buddy here who lives on a 
west-facing hillside that he really ought to cut come drainage 
passages in the privet hedge at the bottom of his garden to let 
the cold air out. No, he doesn't, and he gets pooling of cold 
air and localized freezing in consequence. My former swamp is a 
low spot and the low parts of it are significantly frostier 
than the ever-so-slightly higher parts even though we're 
talking about less than half an acre, less than 300' distances.

And then there are the imponderables. In 1988 I moved about two 
miles from a banana belt to a slightly higher, colder, wetter 
situation. I can't even begin to guess just what causes this 
difference, but I know when I drive home, the street is often 
dry until I'm about a quarter- or half-mile from home and then 
it's suddenly wet, the line of demarcation being amazingly 

And while I'm at it, let's not forget drainage. My backyard has 
standing water after heavy winter rains, but twenty feet away, 
right by the house, the perimeter drains keep the soil 
dry allowing Teucrium fruticans, Convolvulus cneorum, Punica 
granatum flore-pleno, Iris unguicularis, and Cytisus 
battandieri to all thrive. Iris cretensis thrives (more or 
less) raised just a foot above the squelch.

For those of us on the left coast, the Sunset climatic zones 
are far preferable to USDA hardiness zones, taking into account 
as they do a great many more factors than just winter low 

> ...Jim Shields remark regarding the temperature being lower
> in the country, than in the town was quite thought provoking.
> It made me wonder if being close to a major thoroughfare also
> had an influence.

The heat island effect, very well known.

> I do think the climate is warming, but surely this has been
> going on for many years. Way back when the Thames river (
> Roger I refer to the Thames in London, England, comprising
> parts of the counties of Kent, Middlesex, Essex and Surrey and
> a few others) used to freeze over and people walked across the
> Thames, this in the 17th ad 18th centuries. The ice was
> several feet thick.

Hee-hee. You will be relieved to hear that there is also a 
Thames in Ontario, though it's a much smaller stream, so your 
specificity is not entirely out of place.

And I wouldn't be surprised if there are Thameses in NZ, Oz, 
and SA.

[Eeeek: he abbreviated! Sinner!]

In summary: What this business of climate adds up to is a very
complex multi-factorial effect. That's why Sunset's system,
which is based on the observed performance of benchmark
plants, is so superior, even if it means our hypothetical
friend Joe Sixpack has to struggle to read a map and actually
pay some attention to his surroundings. Benchmarking doesn't
just mean hardiness, btw. It includes such factors as "What
bears fruit in this location? Apples? Lemons? Oranges?
Citrons?" (That last being the most tender citrus).

Back to blubs: a local hardware store surprised me with 
packages of Iris 'Katherine Hodgkin', Ipheion 'Rolf Fiedler', 
and a white Ipheion. Amazing.

Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate

on beautiful Vancouver Island

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