Blueberry blooms are incredibly resilient and can withstand cold temperatures to a certain extent. The extent to which they can tolerate the cold depends on the stage of development of the blooms.
At the earliest stage, when the flower buds are still swollen and unopened, blueberry blooms can withstand temperatures as low as 21 F (-6 C). This is quite impressive considering how delicate flowers can be. It is fascinating to see nature’s ability to protect itself from the harsh elements.
However, as the buds start to mature and the bud scales abscise, revealing the individual flowers within, the tolerance to cold decreases. At this stage, when the flowers are distinguishable, blueberry blooms are more susceptible to damage from cold temperatures. They can be killed by temperatures as low as 25 F (-4 C). This means that even a slight drop in temperature can have a significant impact on the survival of the blooms.
Once the flowers are distinctly separated and the corollas are unexpanded and closed, they become even more vulnerable to the cold. At this stage, temperatures of 28 F (-2 C) or lower can kill the blooms. It is important to note that the corolla is the part of the flower that forms the petals, so when it remains closed and unexpanded, the bloom is not fully developed and is more susceptible to cold damage.
It is crucial for blueberry growers and gardeners to monitor weather forecasts and be prepared to take protective measures if temperatures are expected to drop below the tolerance threshold of the blueberry blooms. This can include covering the plants with frost cloths or using sprinkler irrigation to create a protective ice layer around the blooms.
Personal experience has taught me the importance of being proactive in protecting blueberry blooms from cold temperatures. I have witnessed the devastation that can occur if precautions are not taken. One cold spring night, the temperature unexpectedly dropped to 24 F (-4 C), and the majority of the blueberry blooms in my garden were killed. It was disheartening to see the potential fruit crop disappear before my eyes.
Blueberry blooms have varying levels of tolerance to cold temperatures depending on their stage of development. Swollen unopened buds can withstand temperatures as low as 21 F, while buds with abscised scales and distinguishable flowers are killed at 25 F. Blooms with closed and unexpanded corollas are killed at 28 F. It is crucial for blueberry growers to be aware of these temperature thresholds and take appropriate measures to protect the blooms from cold damage.
