Hi Darwin

0F shouldn't be a problem with most vinifera since they have had time to
harden.
However -15F (-26C) will definitely kill a percentage of buds and arms
depending on the variety.
Also some weaker and younger trunks will be damaged which will then make
them susceptible to crown gall. Bottom line you will likely have to retrain
many new trunks next year and this is a real pain since it gets in the way
of typical operations. Much depends on the condition of the vines as they
go into winter (mildew damage, overcropping issues, time to harden ....)

Here is an article on Ontario's experience last year:

http://www.gov.on.ca/OMAFRA/english/...r/tf0801a5.htm

Joe


"Darwin Vander Stelt" > wrote in message
...
> Oregon,Washington and Idaho grape growing areas got some real cold weather
> this week, -15 around Patterson Washington, and 0 in western Idaho. Have
any
> of you heard any damage assessments? Here in western Idaho we had pretty
> good snow cover and own rooted vines so the worst will probably be
> retraining the vines for a year. Interested in any information as I
haven't
> been through this before.
>
>