In article , Nick Maclaren
writes
In article ,
Chris Hogg wrote:
How much does wind chill effect plants? I assume that because it's a
calculated figure intended to give humans some idea of how cold it
feels, then an air temperature of say 2C with a wind chill of say -3C
doesn't actually mean plants will freeze (assuming they would anyway
at sub-zero temperatures). But I also assume that, because of the
effect of the wind, plants will actually reach that 2C much quicker
than they would do in still air, and that their own individual
microclimate within the 'envelope' of the plant would be greatly
reduced or literally blown away.

I believe that a lot of plants are not actually harmed by the freezing
as much as the desiccation. The freezing stops the water transport,
and the ice sublimes in dry conditions, especially with a wind. This
would explain why a single night's frost is less damaging than a
long period of the same temperature.

Similar for wind itself, even without low temperatures - the wind aids
evaporation, increases transpiration, water uptake from soil can't keep
up with the loss through the leaves, therefore the plants suffers the
effects of drought.

With low temperatures there are two mechanisms at work, one the effect
of the temperature (turning nasturiums to pulp, for example), the other
the 'drought' effect - for example potted primulas which are OK until
the pot itself is frozen through and they can no longer obtain water.
But pelargoniums succumb quickly to frost, whereas they are perfectly
capable of coping with drought, so with them it must be the temperature
itself. Ditto cacti.
--
Kay
"Do not insult the crocodile until you have crossed the river"