Mendo Growers Facing Severe Frost Challenges

NEWS RELEASE
February 24 2015

Frost season is here and many Mendocino County farmers are in shock with the early arrival of the serious risk of
damage to their grapevines, according to Aubrey Mailliard Rawlins, Executive Director of the Mendocino WineGrowers, Inc.

Normally grapevines awake from their winter dormancy around mid‐March. Some varietals are earlier and some later.
This year, the warm winter and long stretches of dry weather have confused the biological clock inside each grapevine.
Many vineyards have started to “wake up” with delicate buds opening and the first leaves of 2015 appearing. This
“budbreak” is about 3 weeks ahead of schedule.

A cause for celebration, right? Unfortunately, the threat of frost damage at this time of year is extremely high and
farmers prefer that the grapevines stay dormant, and relatively safe from frost, as long as possible.

This Monday morning temperatures fell below 32 degrees Fahrenheit in many parts of Anderson Valley and Potter
Valley. About a dozen vineyards responded by activating sprinklers systems or wind machines to mitigate the risk of
damage to the green and tender new growth.

Joe Webb, President of the Anderson Valley Winegrowers Association stated “Another record breaking early start to the
growing and frost season is not what we had hoped for. We can only hope for some more storms to lower day time
temperatures, increase nighttime lows and recharge our storage ponds.”

For vineyards that use sprinklers for frost protection the worry is that the ponds ‐ which are thankfully full – won’t hold
enough water for a large number of frost events. And while vineyards that use wind machines don’t have to worry about
“running out of wind”, they are concerned about extra use because of the noise generated by the wind machines. One
Boonville resident has filed a lawsuit against his vineyard neighbors based on the noise and challenged the Right to Farm
Ordinance.

Though wind machines have been in use in vineyards for decades, several vineyards in Anderson Valley have added this
technique to their farming practices during the recent drought as a water conservation tool. In an effort to minimize the
noise impacts as well as remain good stewards of our resources, the Anderson Valley Winegrowers Association (AVWA)
has issued a set of Best Management Practices (BMP) to which all regional vineyards are expected to comply. The BMPs
cover topics like lowering the temperature settings at which the units start, proper maintenance and monitoring
ambient temperature and humidity.

The group also launched a noise hotline in 2014 (phone number is 707‐941‐7441) to help identify the regions most
impacted by noise. In addition, vineyards have created a frost notification system (http://mendowine.com/frost), so
residents can receive the same advanced warning of frost conditions that vineyard managers receive.

Arnaud Weyrich from Roederer Estate points out that bud break varies by location: “Both location and altitude on the
Valley floor affect the timing of breakbreak. Some of our Deep End vineyards show 5% budbreak but our Philo vineyards
have yet to start.” One grower on Signal Ridge reports his vines are already at 90% budbreak.

This is shaping up to be a tough spring for farmers.