Wines & Vines Home
Welcome Guest
July 2014 Issue of Wines & Vines

Virginia's 'Silent Spring'

What growers can do to recover from cold injury reminiscent of 2004

by Tony Wolf
Hunt Country Vineyards
Hilling up: Art Hunt uses mulch to protect his vines against winter injury at Hunt Country Vineyards in New York's Finger Lakes.

Silent spring. That was what some grapegrowers experienced this May, when buds should have been bursting with rapid shoot growth. Instead many eastern farmers saw more widespread evidence of winter cold injury than they expected based on estimates made earlier this year. Typical bud injury was evident, but so was injury to trunks and cordons, which spanned a surprising range of varieties.

The 2013-14 winter will be remembered as a cold, changeable and persistent season. On the whole, the low temperatures experienced throughout Virginia were not that low. Many locations reported lows in the 0° to -3° F range, while a few dipped as low as -7° F.


  • Virginia growers are seeing more widespread evidence of winter cold injury than estimated earlier this year.
  • The article compares the weather conditions and damage in 2013-14 with similar experiences in 2003-04.
  • Avoiding nitrogen fertilization and allowing up to five or six shoots are among the ways to get damaged vines healthy again and back into production.

Reports of injury started rolling in following the early January dip in temperature, when a low of -2° F was recorded at the Agricultural Research and Extension Center (AREC) vineyard in Winchester, Va. The vines at the AREC appeared to come through that event unscathed. Reports of damage to cold-tender vines including Tannat and Merlot arrived soon after. Critical temperatures appeared to be at or below about -4° F.

There were at least five oscillations in air temperature between early January and early March, with the event on March 4 following a three-day stretch of highs close to 60° F.

One grower said that the injury at his vineyard during this most recent winter was reminiscent of what he observed a decade earlier, following the 2003-04 winter season. I went back and read what I had observed following the 2003-04 winter in “Viticulture Notes,” a newsletter I write for the Virginia Cooperative Extension, and was struck by some of the similarities in injury following the two winters.

When did the injury or winter kill occur during the 2013-14 winter? I’m certain that some of the injury occurred as early as the freeze events of Jan. 5-6, 2014, because we were seeing bud kill in tender varieties soon after that. Some of the injury may have occurred as late as March 4, however, when temperatures at the AREC in Winchester dipped as low as 3° F. We noted some trunk splitting in a nearby vineyard in late April. Split trunks appeared to be more common on older, larger trunks than on younger trunks with smaller diameters; multiple-trunked vines often have a mix of live and dead trunks (an argument for multiple-trunk training systems).

As with my 2003-04 report, some of this splitting appeared to be due to the drying of trunks and canes of vines injured sometime much earlier (possibly during summer 2013) as the wood was bone dry and completely discolored. We considered that some injury might have occurred as early as Nov. 24-25, 2013, when we had our first real blast of cold air (see temperature chart on page 77). In this case the vines’ health was compromised going into the winter, and those in poorly drained sections of otherwise well-situated vineyards may have had some increased “dieback” of shoots and potentially greater winter injury incidence.

In addition to the more tender varieties mentioned above, we’ve also seen injury in Cabernet Franc and Cabernet Sauvignon as well as more hardy varieties including Riesling, Chardonnay and Pinot Noir. Injury to early budding varieties such as Chardonnay, Pinot Noir and Cabernet Franc is perhaps consistent with the notion that these vines might have deacclimated some by early March, in time to be damaged by the cold temperatures March 4.

Options for dealing with injured vines
I anticipate that we’re going to continue to observe injury and damage from the 2014 winter, including collapse of some vines that have gone through bud break and begun to develop a canopy. This can occur when some buds are alive but the regenerative vascular cambium tissue is damaged. The first real hot weather of the season puts a strain on the damaged vascular system, and the new shoots collapse when their transpirational loss of water exceeds the ability of their impaired vascular system to transport water. We also may see a resurgence of crown gall as a result of the trunk and cordon injury.

In either case, new trunks will need to be developed, and this will require retraining from shoots that originate from uninjured portions of the vine near the graft union (assuming there are live, latent buds in the graft region of the scion). With no appreciable winter injury during the past 10 or more years, many of us have ceased hilling and de-hilling of vines for cold protection. With very tender varieties, there’s a chance that severely damaged vines may need to be replanted.

Renewal trunk shoots that do develop from severely injured vines will likely be extremely vigorous because they are supported by a large, intact root system. Permit these vines to develop as many shoots as is reasonable (five or six if possible), and keep the shoots well exposed and supported upright on the old trunks and trellis system to minimize shading and permit effective disease management. The injury that I observed was not uniform across entire vineyard blocks, and you may find that uninjured vines (or uninjured trunks on multiple-trunked vines) have more shoots than can be trellised. Be prepared to do some shoot (and crop) thinning where needed in June and July.

Where injury is certain and significant, avoid nitrogen fertilization for this season and consider sowing a cereal (or allow weed growth) under the trellis to provide some competition and reduce shoot vigor. Retain moderate (0.5 to 0.625 inches in diameter) canes next winter to retrain trunks and cordons. You don’t need to remove the injured trunks immediately; there will be time for that after you’ve gained a fuller picture of how much injury your vines might have sustained. Trunk injury (and splitting) may also be observed during the following winter (2014-15).

The appearance of cold-injured trunks is a reminder that we are growing cold-tender grapes in a region where winter temperatures can be marginally acceptable. Drought, excess rain and defoliating diseases (we saw lots of downy mildew problems in 2013) can reduce vines’ capacity for cold acclimation and mid-winter cold hardiness, further increasing the potential for severe injury. Many growers—particularly those who have entered the industry since 2000 or so—have ignored multiple-trunking recommendations, and some have planted very cold-tender varieties. These can be calculated, acceptable risks with small plantings in excellent sites, but the hazards are real and should be carefully considered.

I’ve talked to a few seasoned growers who are using the significant winter injury from the past several months as motivation to rethink their varietal planting scheme. If, for example, you have considerable injury to a Merlot clone that is less than optimal, perhaps now is a good time to replant the block with a superior clone.

Dr. Tony K. Wolf is a professor of viticulture and director of the AHS Jr. Agricultural Research and Extension Center at Virginia Tech. He provides extension resources, teaches an online viticulture course and was principal author and editor of the Wine Grape Production Guide for Eastern North America (2008).

Print this page   PRINTER-FRIENDLY VERSION   »
E-mail this article   E-MAIL THIS ARTICLE   »
Currently no comments posted for this article.

Wines & Vines Home
866.453.9701 | 415.453.9700 | Fax: 415.453.2517
65 Mitchell Blvd., Ste. A San Rafael, CA 94903
Wine Industry Metrics
Off-Premise Sales » Month   12 Months  
June 2014 $562 million
$7,549 million
June 2013 $535 million $7,094 million
Direct-to-Consumer Shipments » Month   12 Months  
June 2014 $87 million
$1,669 million
June 2013 $74 million $1,510 million
Winery Job Index » Month   12 Months  
June 2014 300
June 2013 224 182
MORE » Released on 07.15.2014

Wines & Vines
Packaging Conference
Learn More »

Practical Winery & Vineyard Library
Search the PWV archive »

Direct To Consumer
Wine Shipping Report
Download full report »

  • July 24
    Fresno Food Expo
  • July 24-27
    Taste our Terroir
  • July 25-27
    International Pinot Noir Celebration
  • July 26
    Introduction to Wine Analysis
  • MORE »

Article: Wineries May Lose Internet Domain Dispute »
All these arguments could be levied by any industry associated with any gTLD, new or...
Reader: Doug Barnett
Article: Wineries May Lose Internet Domain Dispute »
Do brands get hijacked now? Even though .wine does not yet exist, are there false...
Reader: Larry Chandler
Article: Resistant Weeds Threaten Vineyards »
Roundup is not benign. It does not always break down in a day or two...
Reader: Robert Rex
Article: Resistant Weeds Threaten Vineyards »
Mitigating water use in the vineyard in the first place is also an applicable tactic....
Reader: Guest
Article: Resistant Weeds Threaten Vineyards »
Having managed vineyards that have used both approaches, I would say that a diverse approach...
Reader: Guest

Directory/Buyer's Guide — Your Wine Industry Marketplace
Advanced Search »
   by Product
 by Company Name or Brand
Browse by Category »
2014 Directory/Buyer's Guide
The Wines & Vines Directory and Buyer's Guide
Wines & Vines Magazine
Digital Edition Now Available!
Wines & Vines Digital Edition Now Available
The Wines & Vines Online Marketing System
The Industry Standard winery marketing application
Latest Job Listings
 Harvest Help
 Napa, CA
Winemaking and Production
 Metro Ny Area Manager
 New York, NY
Sales and Marketing
 On-Premise Sales Reps
 All Territories In Ohio, OH
Sales and Marketing
 Wine Educator
 Glen Ellen, CA
DTC, Tasting Room and Retai
 Pacific Northwest Sale...
 Seattle, WA
Sales and Marketing
 Harvest Help Willamett...
 Sherwood, OR
Winemaking and Production
 Supply Chain Customer ...
 Toronto, ON
General Administration and
 Staff Accountant
 Napa, CA
 Southern California Sa...
 Southern Ca, CA
Sales and Marketing
 Finance Manager, Repor...
 Napa, CA
More Job Listings >>
Follow Us On:

Home  |  About Us  |  Editors  |  Subscribe  |  Print Edition  |  Digital Edition

Advertise  |  Site Map  |  Contact Us  |  Privacy Policy
Copyright © 2001-2014 by Wine Communications Group, Inc. All Rights Reserved.
No material may be reproduced without written permission of the Publisher.
Wines&Vines does not assume any responsibility for any unsolicited manuscripts or materials.