[Market-farming] hard freeze

Wendy & Randy Gray hoemangray at earthlink.net
Wed Apr 4 14:56:11 EDT 2007

We had a very hard frost here in the Hood River Valley (Oregon) yesterday. Inside my minigreenhouse in my uninsulated barn it was 30 and I had the woodstove going!

The orchard frost fans and smudge pots were still going at 7:45 in the morning when I came to work (31 degrees). There is one orchardist who uses water and many of the trees on the perimeter were covered in thick white ice!  I've not seen our entire valley running fans and pots that late into the morning or that early the evening before (9:30 pm)!  It was also quite "black" in the pockets in our valley. I do hope it worked for the many orchardists here...my perenials seem to have done ok...even the lilies that are poking up. 

A few years ago I did try sprinklers on my flowers overnight when we had a September frost -- it didn't work then, but it got very cold and possibly after the sun came up I didn't leave the water on long enough.  But, it was near the end of September, so while I was disappointed, it was somewhat "ok"!

Good luck!  
Wendy in Oregon z6ish?

-----Original Message-----
>From: Bill Shoemaker <wshoemak at inil.com>
>Sent: Apr 4, 2007 6:13 AM
>To: Market Farming <market-farming at lists.ibiblio.org>
>Subject: Re: [Market-farming] hard freeze
>The technique is to turn on the sprinklers just before freezing conditions 
>occur, leaving them running until any ice that forms melts the following 
>morning. As the water freezes, it releases heat. That keeps the plant tissue 
>from freezing. But if the sprinklers are turned off and there is no more 
>free water to turn into ice, there is no more heat released and the ice 
>begins to freeze the plant tissue. That's why the sprinklers need to 
>continue to run until all the ice melts off the plants.
>It can be a monumental task, and expensive. A grower needs to evaluate 
>whether it's more cost-effective to replant or just lose the crop.
>Bill Shoemaker, Sr Research Specialist, Food Crops
>University of Illinois - St Charles Horticulture Research Center
>> >An old trick in orchards is to turn the sprinklers on.
>> So does this mean to leave the sprinklers on all night or to just wet
>> the plants before the temperature drops? -Allan
>Market-farming mailing list
>Market-farming at lists.ibiblio.org

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