<span title="Frost........................?">Frost.......................</span>

Question

about what time in the morning does frost set on the plants and cause damage.

and how does and how does watering them (with irrigation) during the cold hours keep them safe...

Answer 1

about an hour before sunrise! the water is above freezing so what ever has water on it is above freezing, and even if it does freeze it will be 32 degrees and won&#039;t get any colder and 32 degree will not kill the fruit!

Answer 2

Frost begins to set on plants when the air temperature falls below freezing.  That could be any time of the day.  Why would frost occur in the early morning?  Think about that....

When water cools, it gives up one calorie of heat per gram of water that falls 1 degree.  Where do you suppose some of that heat goes if the water is on a plant leaf?  

When water goes from liquid to a solid (ice) it gives up 80 calories of heat (latent heat of freezing) per gram of water.  Where do you suppose that heat goes if the water is on the surface of a leaf?  As long as there is some water and some ice on the surface of the leaf, the temperature of the ice-water mix cannot drop below 0 centigrade.

Answer 3

about 4 or 5 o&#039;clock. alway water plants when its NOT sunny. NO MATTER WHAT.

Answer 4

Generally early in the morning but actually depends upon local weather. watering will reduce frost damage to some extent by keeping temperature balance.However smoking the cropped area by burning wood or leaf also reduce frost damage.

Answer 5

I lived in Eastern Washington (state) for 6 years.  It is a huge fruit producing area, of apple trees, and cherry trees.

If you drive through the miles and miles of orchards, you will notice a few unusually things.  They have sprinklers which stand many feet above the tops of the trees, and they seem to have homeowner sized windmills in low spots in the orchards.

The whole &quot;frost dance&quot; the farmers do in the spring, when the buds are most at risk, and in the fall, when the fruit is most at risk is VERY exact.  The farmers have it down to a science.

The wind turbine looking things are actually giant fans.  They are placed in the low spots in orchards, because cold air is dense and settles into low spots.  It would cause a lot of loss in these spots.  The fans can keep the air moving just enough to prevent frost damage.

The sprinklers are good for when the frost is not going to be too serrious.   The buds become coated with ice.  Ice forming actually generates heat.  That heat is just enough to keep the buds out of danger.  The problem is, if the frost hits early in the evening.  The sprinklers may have to be on (usually intermitently) all night, so that ice keeps forming.  Too much ice can form on the trees, and cause branch breakage.  It works best if the temperature is not going to drop too much, and it only has to be on a couple of hours.

For the truely bitterly cold times, the smudge pots come out.  The &quot;pots&quot;  are placed at regular intervals in the orchard, and the LONG night of keeping those pots burning begins.  Wood, leaves, and sometimes burning tires are added to the pots.  The farmers want to make LOTS of dense smoke in their orchard, which traps the heat from the burning and protects the buds (sometime they have to do this to protect the fruit).

This makes horrible pollution, yet it is understandable that the farmers do not wish to loose their entire crop, and any profit they might have made.

There is no set time for frost to hit.  In agricultural areas (potato harvest here in Idaho) but especially fruit tree areas, there will be a ticker running across the screen of your TV if you are tuned to any local channel, whether it&#039;s the news, or a movie, it does not matter.  The farmers keep an eagle eye on those tickers, and readings in their own orchards.  They do not get a lot of sleep during the frost nights.

Most of them also have radios tuned in their bedrooms which will come on with frost danger warnings, in case a frost sneaks in .

~Garnet

Homesteading/Farming over 20 years

P.S.  During frost danger times, the farmers tend to stay up all night playing poker with friends, family &amp; hired hands, while they drink coffee and eat sandwhiches.  Least that&#039;s what I observed!  Oh yeah....they also get grumpy if a teenage girl beats them.  ~wink~

Answer 6

The temperature at which the change of state occurs as the air is cooled is called the dew point temperature when the change of state occurs at a temperature above freezing or the frost point temperature when the change of state occurs at a temperature below freezing.  So, you can see there is no set time for the dew or frost point.  Your local weather channel will give you the expected time of the dew or frost point. It usually will take only a slight increase of temperature at the level of the plants to avoid frost forming.  Adding irrigation water can warm the plants and the air around them enough to prevent frost from forming if the temperature is at freezing or slightly below freezing.  Creating a breeze of stirring the air can also keep frost from forming because warmer air rises and stirring the air can keep warmer air near the plants.  If the  temperature really drops below freezing there is nothing you can do to help enough to prevent plant loss.

Answer 7

Frost settles at night on everything.  Watering plants at night instead of during the heat of the day is better for them.  Part of the reason is how photosynthesis works. The pant is better fed at night so that it  can photosyntesize during the day.

Answer 8

it all depends on the time, it usually happens during the early early hours

well the plants would burn because by watering them -like all over the leafs and stuff - the water intensifies the rays which can be bad. - however, if you want your plants to grew better, water them early morning under the leafs if possible. plants use most of the water when there is sunlight when photosynthesis occurs. i dont know why people water late at night....i think its jsut stupid