Cold temperatures during night from May 24th to May 25, 2022

Cold temperatures were recorded at weather stations in Ellsworth, Eastbrook, Steuben, and Deblois.  Temperatures were below 35 F from about 11pm to 6am over the night of May 24th to May 25th.  Temperatures below 32 were present for 2 to 5 hours.  The weather stations did not record temperatures below 28F at any of the sites but they are only a single point measure within the field.  Other fields near by may have had lower temperatures.  Two years ago cold temperatures (in many fields below 30F) during bloom killed flowers in some fields but also affected set fruit by killing them internally so they did not develop.   If you are concerned about your field, you can cut open some set fruit in low lying areas to see if they are darkened inside which indicates cold damage.

Temperature effects on wild blueberry flowers and leaves according to Hall et al. 1971, Hall and Hildebrand, 1988, and Hicklenton et al., 2002.

Temperature Damage
30.5°F Slight injury to flowers, little effect on fruit set, occasional necrosis at edges of leaves
28 °F Greater than 2 hours,  40 to 60% loss of fruit set in open flowers and 20 to 30% in closed flowers, unclear if berry weight is affected
26°F Open flowers, after 2 hours, 75% of flowers lost resulting in little fruit set.  After 2 hours, 50% of closed flowers do not open, but if they do open, little effect on fruit set. With increased time, fewer flowers open.
Below 24°F Flowers die, no fruit set, leaves are water soaked and may not recover