Cold Weather Update

Cold Weather Update January 2026

Gina Fernandez1 and Hannah Lepsch2

1Extension Specialist and 2Research Assistant/PhD student

NCSU Dept. Horticultural Science

A recent storm producing ice, sleet, and snow across North Carolina has raised understandable concerns about potential cold damage to blackberry crops. While colder temperatures are still forecast, early observations and data provide useful insight into what growers should expect and what to monitor closely in the coming weeks.

Ice Storms: Limited Cane Damage Observed So Far

Ice accumulation varied across the state, with some areas experiencing significant  accumulation of over 0.05 inches (Figure 1). In many fields, blackberry canes were coated with ice (Figure 2); however, there is currently no evidence of widespread cane breakage or structural damage from ice weight. Blackberry canes are generally resilient during dormancy, and past experience suggests that ice alone rarely causes major injury.

Figure 1. Ice accumulation across North Carolina,  Jan 24-25, 2026. Courtesy: NC Climate Office. 

Figure 2. Ice accumulation on 'Von' Blackberry, western NC. 

(NOTE: Do not use overhead irrigation for frost or freeze protection in blackberries. Past events have shown that overhead irrigation in the spring to protect buds can increase ice load on canes and result in cane breakage, often causing more damage than protection)  

Cold Temperatures and Bud Damage

To better understand cold tolerance this winter, buds of ‘Ponca’, ‘Ouachita’, ‘Von’, and ‘Galaxy’ were collected in early December 2025 and early January 2026 from three locations in North Carolina: the Coastal Plain, Piedmont, and Mountains. Buds were evaluated for cold injury following exposure to a range of low temperatures. 

Results showed that:

• In both December and January, more than 50% of buds were killed at temperatures near -6°F at the Coastal Plain site.
• In the Piedmont and Mountain sites, bud kill reached 50% at temperatures closer to 0°F 
• 'Ponca' has shown damage in the mid teens.
• Temperatures recorded at these locations have not reached these critical thresholds, suggesting that widespread bud loss is unlikely at this time. 

Additional bud sampling is planned later this week to further evaluate bud survival following recent cold events. 

Cold temperatures and Cane Damage

In addition to bud injury, cold temperatures can also cause damage to blackberry canes. Over the next few days, forecasted lows below 10°F may increase the risk of cane injury, especially in exposed sites or on less cold-hardy cultivars.

Cane damage is not always immediately evident. In many cases, symptoms may take several days or even weeks to appear. Dead or severely injured canes often turn brown or gray, rather than remaining green and healthy. In some situations, damage is not obvious until spring, when floricane buds begin to leaf out but then shoots wilt or collapse shortly after growth starts.

Because of this delayed symptom development, growers are encouraged to be patient and continue monitoring canes as temperatures warm.

Chill Accumulation: Generally Adequate Across the State

Chill hour accumulation is another important factor influencing blackberry performance in spring. As of late January:

• Coastal Plain: approximately 673 chill hours

• Piedmont: approximately 861 chill hours

• Mountains: approximately 893 chill hours

Most blackberry cultivars require 300–900 chilling hours, indicating that chilling requirements have largely been met across North Carolina. Adequate chill accumulation supports uniform bud break and flowering as plants move out of dormancy. 

Deacclimation: Why Spring Buds Are More Vulnerable

As winter progresses into late winter and early spring, blackberry plants begin to deacclimate, meaning they gradually lose cold hardiness as chilling requirements are met and buds prepare for growth.

Because of this:

• Buds become more sensitive to cold as spring approaches

• Temperatures that would not cause damage in mid-winter can be damaging later

• Spring killing temperatures are higher than winter killing temperatures

This is why late winter and early spring freezes often cause more visible damage than colder mid-winter events.

What Growers Should Do Now

• Monitor forecasted low temperatures closely, especially over the next several days

• Delay pruning decisions, particularly in colder regions, until cane and bud survival can be assessed

• After a period of warmer weather, cut buds and canes to evaluate tissue color, healthy tissue will be green, while damaged tissue will be brown or black (Figures 3 and 4).

Figure 3. Primary bud of blackberry is brown/black and is dead. Note that the secondary bud is still green. 

Figure 4.  Blackberry cane showing browning just under the bark, this is vascular damage. 

Bottom Line

Although winter weather has been challenging, current data suggest that temperatures so far have not been low enough to cause major bud loss in most areas of North Carolina for most of the cultivars we studied (except 'Ponca'). Bud and cane injury remains a possibility following upcoming cold nights and throughout the spring, but symptoms may take time to appear. Continued monitoring over the next several weeks and months will be key.

Additional updates will be shared as new data become available.