Our old and young apple trees seem to be bearing up stoically so far under pressure from freezing polar vortex temperatures. The trees’ cells apparently are adapting by producing arboreal “antifreeze” that allows water to freeze safely among cell walls and prevent harmful ice crystals.
The big danger, as I understand it, is that the cold can get so extreme and prolonged that the water in dormant tree sap freezes, expands, and creates a bark explosion that can wound or kill a tree. (Image taken in Brooklin, Maine, on February 19, 2025.)