I've looked for a map like that too. Doesn't seem to be one online I can google. Love to see one too. RJ

I doubt such a map would be of much value, the overwhelming majority would be 9-11 and consider the differences between, say Pretoria and cape town, even though both have similar winter lows. (This is the reason why most California gardeners have little use for USDA zones, most of the state is 9 or 10, but there is an enormous difference between Salinas and Death Valley even though both are zone 9).

Probably have a point there. Incidently your links to weather.com were very informative , great resource I did not know about. Gee looked up Johannesburg and it threw up Johannesburg in Michigan and Johannesburg in California . Knew about the one in California where there was a short lived gold rush but not the Michigan one.

The Sunset zones used in California may actually be more useful come to think of it. They are more bio-zones and the climate is somewhat similar to SA. Maybe that's the ticket and we can refer to the Sunset zone map easily for the whole US from their website. RJ

Yes RJ I think the Sunset Zones are far more useful if we are going to tackle this. Thanks ...great idea. Its going to be quite an undertaking if we decide to give it a go!

Maybe as a start we can gather what up whatever maps do exist on S.A. climatic regions eg. there is a map showing the biomes , I have a map showing the intensity of the frost over the country , there will be an elevations map somewhere , also somewhere will be a rainfall map , minimum and maximum and average temperatures etc.

If we sort of super-impose / combine these we could arrive at a point where we can roughly define which zones would apply to where.Any revisions could be brought in later. Certain of the California zones apply to areas which are sort of unique climatically . These we can adapt to apply to similar unique areas in S.A. , which we will most probably encounter.
How about giving it a go and see what we can come up with? If anyone has any experience in climatology , cartography etc and is prepared to help this would be great but no experience is necessary ... we will figure it out / learn as we go along . Garrick

I'm a total amateur but I'd volunteer to do some labor if we can find a knowledgeable leader. RJ

Hi
I've found the Plantzafrica site useful at least for plant ID. I live in zone 10 Florida and apparently SA has a similar climate at least in coastal areas. Obviously a lot of microclimates with widely varying rainfall.
The winter growing summer dormants interest me as I could do this artificially.A zonal map would sure eliminate a lot of trial and error
Gary

just for the heck of it, i will make some very tentitve suggestions about assigning sunset zones to parts of s.a. (these hopefully will serve as a springboard for discussion and perhaps much more realistic input from more knowledgable people on this complicated subject. my sources are both the sunset "western garden book" and the sunset "national garden book" (which expands the basic sunset zones to the rest of the country including warm, summer wet areas like florida, south texas, and the gulf coast), and the very useful "garden beauty of south africa" by sima eliovson. here goes: cape town and coastal environments (24), port elizabeth area (23), port elizabeth to durban (26-28) durban is 25, johannesburg (18/20), pretoria (19/21), free state (29/30), karoo (9,18, 12,13) franschoek and winelands area (16). as i say, these are at best guesses since there are many areas thruout the country even in the relatively temperate areas that have no close approximation to any continental sunset zone because they combine yeararound precipitation with mild but not hot summer temps like the knysna region or pietermaritzburg or hot relatively moist summers and cold dry winters experienced by areas of the free state. any comment or input would be appeciated---what do you think?

george, what did you use for the weather data? Just curious...RJ

weather info used to make the zone suggestions was from a table in the book "garden beauty of south africa" by sima eliovson (from data supplied by the weather bureau, pretoria) and from discussions on both local weather and plant species both native and exotic that were said to do well under cultivation in those areas.

Well George, sounds like you are our only contestant. Garrick, you want to add something to this?

I was waiting to see if anyone has other info. Don't know any better than what George has done but if someone has some raw data to process I can handle that for the group. RJ

Going by temperature the zones may be accurate (I'm not going to go to the trouble of checking), but several sunset zones are winter-rainfall regimes (particularly zones 8,9;14-24) and as you noted, the continental U.S. doesn't have much in the way of dry winter areas. Perhaps a modification in which you indicated the season of greatest precipitation, for instance 21s for a predominantly summer rainfall regime (capital S if winters are almost totally dry) with average winter lows around 45. A possible modification for areas along the garden route could be 23/24ws possibly capitalizing one or the other for areas that get more in one season than the other, but don't quite fit one of the other zones. Anyway, you get the idea, Durban would then be 25s.

the nice thing about sunset zones 25, 26, 28, and so on are that they are summer wet zones (from the gulf coast to south florida) so they have at least some relevance to parts of south africa. ultimately it will probablly have to be a system of trial and error to find/create a zone system that will allow people in both the u.s. and s.a. to make intelligent climate comparisons and plant choices for their gardens. btw, the book "the looking-glass garden" by peter thompson discusses many s.a. natives as garden plants in the northern hemisphere and assigns usda zones to many of them (for whatever thats worth). its a generally good read with some very useful information and i recommend it to the people who frequent this board.

Garrick -
One way to divide it is with "indicator plants" ...

Look at desert-tropicals.com and see what it says about S AF plants that you are familiar with. If Aloe whatever is native to the Cape Town area, and thrives in Phoenix with similar care, you have a match.

Been out of the discussion due to computor problems. Have not had much time to devote to research as fixing a computor is very time consuming , especially if you dont know exactly what you are doing. The repair is not yet 100% correct so will get back to you when possible. Garrick.

That won't necessarily work lazygardens, you can grow (for instance) Bougainvillea, in Phoenix, Cape Town, Durban and Los Angeles, but the only two of those climates sharing any real similarity are Los Angeles and Cape Town.

SoCal -
Then Bougainvilla is not an "indicator" species for climate.

I think Phoenix and the Karoo match up well.