Re: Bloom seasons in northern and southern hemispheres

Mark Brent wrote: 
Dear Cheryl,
Your query about the comparative flowering seasons between Southern
hemisphere plants and their Northern counterparts is something that
intrigued me after I made a trip down to the Western Cape, South Africa last
autumn.

Quite a few woody species, native and alien were either at a similar stage
in the flowering cycle, Leucadendron and Acacia spring to mind, or not far
behind in their development back home in Cornwall (some Protea sp.). However
the same could not be said of some of the Myrtaceae I saw, several
attractive scarlet Metrosideros excelsa by the sea at Camps Bay reminded me
that ours made its display way back in the British mid-summer, (probably a
sensible idea given the current weather here).

> By speaking to staff at Kirstenbosch I understand climatic change is
> becoming a serious concern (rainfall was one factor) for them, as much as it is for us which clearly throws some of the plants out of their traditional cycle with ourselves of late, which muddied my thoughts further.

Hi
In the case of the Metrosoderos I should just like to point out that this is a New Zealander not an Australian. Here it is certainly only in flower in midsummer, being commonly known locally as the Christmas tree, a role which it faithfully and beautifully fulfils.

I find this posting generally interesting as it chimes well with the notion expressed in an e-mail from Chas about the seasonal flowering linkage being strongest in temperate species and less strong in plants from nearer to the equator. He gives us his experience with Kapok and I can recall a similar effect with the avenue of flame trees (Spathodea nilotica) on our Kenya farm which never made as much impact as my parents had hoped because, like the kapok, the various trees leafed, rested or flowered to no discernable pattern (not even as one might have expected did flowering seem to be in any way linked to the coming of the rainy season). Among southern hemisphere species, while almost all Proteaceae are indeed southern plants the majority come from either South Africa or Australia, which are both at least half within the tropics if not actually near to the equator and so getting into that region where daylength is less variable and temperatures not so markedly different between cold and hot seasons. In contrast New Zealand, and the part of South America where Proteaceae grow is entirely within the temperate zone with its more clearly marked seasons. Another example would be the tropical (Vireya) Rododendrons which will flower any time the fancy and even several times a year.

Of course, we in NZ likewise grow Northern hemisphere plants in our Southern seasons, and I think all the ones from temperate latitudes do reverse their seasons almost exactly, with, for instance, Camellias flowering from late winter and Rhododendrons at various dates throughout spring, climaxing in October (aka May). Forsythias flower from winter into spring and Fuchsias only during the warmer months with longer daylength (not quite sure which of these is the trigger). We have however here recently had some species flowering out of season (the odd Rhodo in early autumn for instance) which we are ascribing to the disrupted weather patterns we have been experiencing, as they have at Kirstenbosch.

Nothing weatherwise seems all that predictable any more.

Moira

--
Tony & Moira Ryan,
Wainuiomata, North Island, NZ.     Pictures of our garden at:-
http://mywebpages.comcast.net/cherie1/Garden/TonyandMoira/index.htm
NEW PICTURES ADDED 4/Feb/2004

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