On 22 Mar, 00:47, "Chris S"
wrote:
"Dave Hill" wrote in message

oups.com... It has always struck me as strange that some young plants can take
frost, snow etc when only just emerged from the ground, whilst when
they are mature the first frost will kill them,
I am thinking of plants like sweet peas.

David Hill
Abacus Nurseries

It's presumably a biochemical response - not one I'd thought of before - so
thank you for giving me something else to ponder over :-)
It would appear than in spring, the cold response is to strengthen and slow
growth, while in autumn, the same stimuli promotes decay. I'm sure research
has been done on trees in the autumn to see what prompts leaf drop - i.e.
which set of chemicals.
Very interesting......
Chris S

The chemistry of leaf drop has been well researched but don't take it
for granted that all aspects of plant metabolism have been well
studied. Far from it, our understanding of plants is still very
sketchy compared with that of animals. Frinstance it's a fairly recent
finding that plants give off a small but measurable amounts of
methane. Why wasn't this discovered long ago? Because no one dreamt
that this could happen so nobody looked - simple as that. The amount
involved is not significant in global warming so please don't stop
planting things.