Frosts, supercooling, and other fun stuff

J.E. Shields
Wed, 14 Nov 2007 05:30:54 PST
Joe and all,

This discussion of Frost has been interesting.  I am also puzzled by the 
"protect from sun" argument.  Here are my musings, trying to make sense of it.

Planting tender plants on the shady side of houses, hills, trees, etc., 
makes sense as was mentioned earlier by someone in this thread:  Fewer 
freeze-thaw cycles means less physical damage to the plant tissues.

The coldest temperatures seem to be reached shortly after the sun has risen 
in the morning.  I've watched this effect with my remote thermometers.

Joe accurately describes the effects of spraying with water.  The watering 
has to start before there is any freeze damage to the plants, of course; 
otherwise it will  not protect completely, but merely reduce the extent of 
damage.  This is the only point I can see to watering on a frosty morning 
just before the sunshine hits the frozen surface; watering would have to 
happen just as the freeze damage point is being reached to be 
protective.  Otherwise, there seems to be no physical chemistry sense to 
the notion of watering just before the sunshine hits the plant, after the 
freeze damage has happened.  So I must assume it is "folklore" or non-urban 
legend until someone can show me the physical chemistry to prove otherwise.

Best wishes,
Jim Shields
in central Indiana, where the frost is due again any day now.

At 10:42 PM 11/13/2007 -0600, you wrote:
>  Hi Gang,
>1. I'm still confused about the sunshine vs. warm water notion of reducing
>damage to plants that have gotten too cold. Wives' tale or note, the notion
>persists and some folks seem to have good luck by pouring water over their
>plants before the sun shines on them. I can't figure it out.

Jim Shields             USDA Zone 5             Shields Gardens, Ltd.
P.O. Box 92              WWW:
Westfield, Indiana 46074, USA
Tel. ++1-317-867-3344     or      toll-free 1-866-449-3344 in USA

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