In article ,
"brooklyn1" wrote:

"Denis Mitchel" wrote:

Does the temperature have to be at or below freezing for frost to form on
plants?

No. The dew on plants can freeze without the air temperature dropping to
below 32ºF... this often occurs with lawns and other low growing plants
because even though the air near the ground is heated by the radiant heat to
above 32ºF yet the fine droplets will freeze...
Because . . . . ?
fog can freeze and settle on
plants (like snow).
Fascinating, can we have a cite?
But just because the dew freezes on the plant doesn't
mean the plant freezes,
Uh huh, I think we already covered the heat of fusion.
many plants contain chemicals that act as
antifreeze, and many plants will suffer 'frost' damage above freezing,
especially young tender seedlings.
There's good reason why weather
forcasters mention "dew point", has to do with barametric
pressure/elevation.
And that reason is . . . ?

Whatever the true identity of brooklyn1, brooklyn1 certainly is as
scatter brained as Shelly, who has a thing for forest pansies, heh, heh
(as Shelly would say).

Still, one last wrinkle. Wind chill could allow standing water, as small
as a dew drop even, by evaporative cooling in conjunction with low
temperatures.
--

- Billy
"For the first time in the history of the world, every human being is
now subjected to contact with dangerous chemicals, from the moment of
conception until death." - Rachel Carson

http://www.youtube.com/watch?v=WI29wVQN8Go

http://www.haaretz.com/hasen/spages/1072040.html