"Linda H" wrote in message
I'd be interested to hear other's views on frost, too Kylie.

I live in the Yarra Valley (Vic.) and recently a surprise severe
frost
took its toll on some of the big vineyards (Oct or Nov I think?)

The particularly bad frost that hit a huge area of NSW and Vic was in
October. One of the worst I've ever seen as it bit the leaves on very
big trees and I've never seen anything like that before in my life.

What I did notice particularly was that the obvious damage was to
where
the vines were at their lowest at bottoms of hills.

Yep. Frost drained downhill to the lowest point. Never buy land in a
frost pocket :-))

On that morning the bigger vineyards had helicopters going over them
but
they still lost a lot of crops. It made me wonder what they do when
a
severe frost is forecast. Do they drag mesh or some other
protection
over them? (Like the bird nets they drag over them?)

There are a number of ways of dealing with frost commercially but the
most common that I know of is to spray water over the plants or to use
fans to create air movement. The old way was to light fires and
create lots of smoke. The trouble with the big October frost for
vineyards round here was that the cold snap went on for so long that
the water ran out and then the water droplets froze on the plants and
did more damage. The commercial producers have it all on electronic
command so they can now stay snug in their beds.