2026 Grapevine Spring Freeze Injury: What to Expect, Next Steps, and a Survey

Unseasonably warm, at times hot, temperatures in late winter and early spring 2026 led to early bud break in many Pennsylvania vineyards. As part of the Penn State "Grapevine Growth Progression Across Pennsylvania" project, we are tracking growth stages across multiple cultivars and sites. Based on data collected from grower cooperators to date, cultivars such as Chardonnay, Cabernet Franc, Pinot Grigio, and Riesling reached budbreak around April 15–18, particularly in southern Pennsylvania. In some cases, later-budbreak cultivars such as Vidal blanc reached budbreak only a few days after earlier cultivars like Chardonnay, highlighting the rapid and compressed progression of development under these conditions. While early bud break can extend the growing season, it also increases the risk of exposure to below-freezing temperatures (frosts/freezes) and subsequent cold injury to green, tender grape tissues through at least mid-May in many Pennsylvania vineyards.

Spring cold injury events can kill primary and, in more severe cases, secondary bud tissues. While vines can continue to grow and maintain perennial health through shoots emerging from secondary and tertiary buds, these shoots typically produce significantly less crop than those from primary buds. As a result, spring cold injury events can limit crop yield and, ultimately, vineyard profitability. Importantly, reduced crop potential does not necessarily translate to lower management costs, as frost-injured vineyards still require full-season pest and disease management.

This risk became a reality during a frost/freeze event that occurred from the late hours of April 20 through the morning of April 21, resulting in widespread frost injury in Pennsylvania and regional vineyards. Based on weather data from on-farm stations accessible to our team, minimum temperatures reached approximately 19.8°F at Rock Springs (Penn State research farm), around 23°F in parts of Lancaster County, 24°F in Lehigh/Schuylkill counties, and approximately 25°F at farms in Union and Snyder counties. Based on reports from grower cooperators collected to date, the majority have observed widespread damage across cultivars.  In some cases, the extent of injury appears to vary among cultivars. Reports from growers also indicate that several frost protection strategies were implemented during this event, with the use of open fires being among the most common approaches.

However, given the geographic variability, site-specific mesoclimates, and differences among cultivars, not all vineyards are expected to have experienced injury. Where injured occurred, it is likely to be highly variable within and between vineyards (see Figure 1 for an example of cold-injured shoots in low-lying areas of a vineyard block). In general, shoots at more advanced growth stages (e.g., 2-3 leaves unfolded) are more susceptible to cold injury than those at or near budbreak, but some events are severe enough to cause widespread damage across growth stages. In our research vineyard, where minimum temperatures reached approximately 20°F, visual observations following the April 20-21 freeze indicated that even less advanced shoots experienced severe injury, with the majority appearing dead (Figure 2). At this stage, it is still too early to determine whether damage extends beyond green tissues (e.g., to vascular tissues).

What to do next?

At this point, many are likely asking, "What should I do next?" The general recommendation is to wait and observe, while continuing your pest and disease management program as you would under "normal" conditions, given that clusters are not developed yet. The desire to react and "do something" is well understood, but there is little that can be done at this stage to recover lost crop potential.

It is important, however, to anticipate what may happen next. Crop yield will be reduced if primary (or even secondary) buds or shoots, or primary cluster tissues, are killed or severely injured. The extent of crop yield reduction will depend on the severity and distribution of primary and secondary bud and shoot injury (see Figure 3 for an example of healthy and cold-injured primary shoots on the same vine in a Pennsylvania vineyard in May 2023). If the outcome is a mix of primary and secondary shoots, this presents a unique situation, as these shoots will differ in growth stages and fruit ripening timing throughout the season.

For pest and disease management, vines should be managed based on the dominant growth stages present in the canopy when critical fungal disease management window occurs. In vineyards with a mix of primary and secondary shoots, this requires careful consideration of which growth stage represents the majority of shoots.

Be mindful of seasonal maximum application limits and pre-harvest intervals on pesticide labels, as these will expire sooner for primary shoots and fruit than secondary shoots and fruit. For more detailed guidance, please see this recent publication by Mizuho Nita at Virginia Tech: Frost, Disease Risks, and a Downy Forecast. Additional resources are outlined at the end of this article.

A mix of primary and secondary shoots will also affect fruit ripening and harvest decisions. Growers might consider developing a plan for managing this variability, such as thinning either primary or secondary clusters (depending on their relative abundance), harvesting fruit separately for different wine styles, or harvesting all fruit together. Additional considerations are outlined in the "After the frost" section of the University of Georgia "Vineyard Frost Protection" extension publication, in the April 2020 "Viticulture Notes" by Tony Wolf, and in a recent blog post through the Virginia Tech Viticulture Extension Program by Drew Harner.

Important:

To help us better understand the extent and impact of the spring 2026 cold injury event(s) across vineyards, we encourage you to complete this survey, developed by Jennifer Phillips-Russo, Cornell Lake Erie Regional Grape Program Team Leader and Viticulture Specialist. NOTE: this survey has already been distributed through other Extension outlets over the last week in our region; to limit duplicate data, please ensure that only one response is recorded from your vineyard. For questions about this survey, please email Jennifer at jjr268@cornell.edu.

We also encourage you to provide feedback by taking this survey created by the Pennsylvania Farm Bureau (again, please – one response per vineyard operation).

The Penn State Extension Grape and Wine Team is hosting the first of its monthly virtual office hours for Pennsylvania grape and wine industry stakeholders. The meeting will be held from 2:00 to 3:00 PM ET on May 26. You can join via Zoom. We suspect the April freeze event will be an important topic of discussion.

In the meantime, please feel free to reach out to us on the Penn State Extension Grape and Wine Team with any questions or concerns regarding spring cold injury in your vineyard.