Real-Time Monitoring
Variety Graphs
BUD10 is the temperature at which 10% of the primary buds will be killed; BUD50 and BUD90 refer to 50% and 90% bud damage, respectively. PHL10 is the temperature at which 10% of the phloem (bark) is damaged or when cane damage is starting. XYL10 is when phloem damage is complete and xylem (wood) damage is starting. This would be considered severe cane damage. Grapevines can survive more than 50% phloem damage and still be productive. When xylem becomes damaged, grapevine productivity and survival can be compromised.
Select a variety name below to see the current season observed cold hardiness.
In the Spring
When we are at or approaching bud break, we will not be able to run exotherm analysis in grapes any more. In previous years we have included the critical temperatures for several different varieties during the period leading up to bud break. Since every variety responds differently to cold, this should be used only as a rough guideline.
- Cabernet Sauvignon at first swell sustained no damage down to 25°F.
- Merlot at full swell showed slight damage to the buds, phloem, and xylem at 25°F. More serious damage to the phloem and xylem occurred at 23°F.
- Chardonnay at budbreak showed slight damage to the buds and phloem at 27°F. More serious phloem and xylem damage occurred at 25°F. Buds were seriously affected at 24°F.
Resources
Preventing Cold Damage in Grapes:
Assessing Cold Damage in Grapes:
- Assessing and Managing Cold Damage in Washington Vineyards – WSU #EM042E
- ESPAÑOL – Evaluación y Manejo del Daño por Frío en los Viñedos de Washington
- Winter Freeze Damage and Vine Fruitfulness (PDF): Why does cold damage impact yield? – WSU Whitepaper
- Anatomy of Winter Injury (PDF) – Cornell University
Responding to Cold Damage in Grapes:
- Effect of Pruning on Recovery and productivity of Cold-Injured Merlot Grapevines – AJEV 2007 58:351-357
- Vine and Vineyard Management Following Low Temperature Injury – ASEV 2000 Cold Hardiness Workshop
Modeling
Washington State University has developed a Cold Hardiness Model to predict grapevine cold hardiness anywhere temperature data is available. It is available both as an EXCEL sheet (to enter your own weather data), or via AgWeatherNet (for WA locations).
More information on modeled cold hardiness can be found at our Cold Hardiness Modeling page: http://wine.wsu.edu/extension/weather/cold-hardiness/model/
Seasonal Summary
Initial Cold Hardiness, Maximum Cold Hardiness, and Spring Frost Tolerance
The below table shows initial fall cold hardiness (mid-September) and potential maximum mid-winter cold hardiness for grapevine buds. It also shows frost tolerance of green tissue in the spring following budbreak.
Information is modified from Table 4 in Ferguson et al., 2014 (AJEV).
Variety |
Initial Fall Cold Hardiness(°F) |
Potential Maximum Mid-Winter Cold Hardiness(°F) |
Frost Cold Tolerance- Post Budbreak(°F) |
| Barbera | 13.8 | -10.3 | 29.8 |
| Cabernet franc | 14.2 | -13.7 | 29.8 |
| Cabernet Sauvignon | 13.5 | -13.2 | 29.8 |
| Chardonnay | 10.8 | -14.3 | 29.8 |
| Chenin blanc | 10.2 | -11.4 | 29.8 |
| Concord | 9.0 | -21.1 | 27.5 |
| Dolcetto | 13.8 | -9.8 | 29.8 |
| Gewurztraminer | 11.1 | -12.8 | 29.8 |
| Grenache | 14.0 | -8.9 | 29.8 |
| Lemberger | 8.6 | -14.1 | 29.8 |
| Malbec | 11.3 | -13.2 | 29.8 |
| Merlot | 13.5 | -13.0 | 29.8 |
| Mourvedre | 14.9 | -7.8 | 29.8 |
| Nebbiolo | 12.0 | -11.9 | 29.8 |
| Pinot gris | 10.4 | -11.4 | 29.8 |
| Riesling | 9.3 | -15.0 | 29.8 |
| Sangiovese | 12.7 | -7.4 | 29.8 |
| Sauvignon blanc | 12.9 | -12.8 | 29.8 |
| Semillon | 13.3 | -8.3 | 29.8 |
| Sunbelt | 10.8 | -20.4 | 27.5 |
| Syrah | 13.5 | -11.6 | 29.8 |
| Viognier | 11.8 | -11.2 | 29.8 |
| Zinfandel | 13.3 | -11.9 | 29.8 |
