What is a Mediterranean climate?

Mary Sue Ittner msittner@mcn.org
Thu, 04 Feb 2010 13:12:31 PST
Dear Mike,

Like others I appreciate all the time you have spent on this and 
think it will be a great resource. Perhaps another option so all of 
us could read the keys would be to use a font that works on all 
platforms. If the pdf file gets too big for our wiki limits Nhu, 
David, or I can transfer it in. We allowed a couple of Lee's maps 
with larger file sizes. If they were smaller, making out the details 
was tricky. And I think at least one of the maps with a large file 
size, Nhu added a smaller version too so that you had a choice 
whether to download the larger version if you had a slow connection.

I think perhaps we should create a climate wiki page linked to the 
home page and they link your page and Lee's two pages to it. I 
suppose we could also link all those discussions we had a number 
years ago when we did the topic of the week on which bulbs to grow in 
different climates/areas.

Like Bracey I think the issue is very complicated and that knowing as 
much as you can about where the plant grows naturally is helpful. 
We've talked before about when to start watering dormant pots. 
Although Gordon Summerfield in South Africa who has grown many South 
African plants suggested that we could wait until October in the 
northern hemisphere, I've found that is too late for some things. If 
they aren't started into growth earlier like they would be in South 
Africa, they don't always bloom. Perhaps they need a certain length 
of time to grow before they will bloom.

Whether dormant pots need to be watered in the summer in dry areas 
may also depend on whether the "bulbs" (all inclusive term) continue 
to have roots during dormancy. If they do and the pots dry out too 
much so that these roots dry up completely, the stress may be so 
great the plant is always struggling to recover. On the other hand if 
every year the plant produces a new corm or a new rhizome, it may not 
matter as much. Now that I water my Nerines in summer they flower 
much more frequently. But my Romuleas seem to do fine without summer 
water even if they are exposed to rainfall in South Africa in summer.

Because of the font problem I can't look at all your data, but can 
Australia really be described as having a "milder" summer? I thought 
temperatures got really hot in summer in a lot of the states except 
for Tasmania. I grow a lot of Australian plants successfully with 
little summer water and live in on the coast so that fits your 
theory. But just because we have cooler temperatures and some fog, if 
you dig down in the soil much below the very top, you find it is 
absolutely dry in summer. Having a lot of Coast Redwoods means their 
roots are soaking up any available moisture. I look for plants to 
grow in my garden that come from areas with low nutrient soils since 
that is what I have and I think that is one of the reasons I can 
successfully grow a lot of South African and Australian plants. I 
find that Western Australian plants (often considered to be 
Mediterranean) don't last long in my garden however. I've always 
thought they needed more heat in summer or that it was too dark and 
wet in winter for them.

Besides the Arctic Express problem that can wipe out collections of 
people who live in areas where usually it doesn't get cold, but can 
on occasion, there are also the El Nino factors. For a number of 
years we have had a "drought" where I live. Our droughts mean that 
rainfall could be between 30-40 inches (76 cm-101cm.) This stresses 
the trees and plants used to more rainfall, dries out the rivers in 
summer and is not good for the wildlife. But it is still a lot more 
rainfall than naturally occurs in some of the areas where bulbs I 
grow originate and a lot of them grow much better in a drought year. 
If you have a year like this one where we seem to be getting some 
precipitation almost every day lately some of the bulbs that are 
happy in the drought start to rot or the leaves get grey mold. And 
the lack of light means others are getting floppy.

Thanks for taking this on. You've added information to the wiki that 
will be very useful to a lot of people including all your cultivation 
information too.

Mary Sue

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