So next night we’ll have -20 F (-29 C). This is probably the coldest temperature in 20 years. And we had several nights at -10-15 F range and would probably will get more of them. I became interested in winter hardiness of various trees and my conclusions are not very promising. Based on the cold that we will have next week (and it might be worse at the end of the winter) most of the trees will have damage to the fruit buds and many might also die. The most sensitive to killing cold are hybrid persimmons (-25 C), peaches (-25 C for fruit buds and -28-30 C for wood), sweet cherries (-25 C for fruit buds and -27-30 C for wood), jujube, pawpaw, mulberries, quince (all up to -30 C for wood) and probably Asian plums. A little bit more hardier will be apricots (-28 C for fruit buds and up to -37C for wood), apples (-35-40 C for wood), pears (-30-35 C for wood), European plums and American hybrids (-38C for wood) , American persimmons (-35 C wood), sour cherries (-32-34 C for fruit buds and -38 C for wood).
All the data is very general and the actual hardiness depends of many factors. Many varieties are not selected for winter hardiness, so even apples, pears and plums will be damaged. I just hope that my grafted peaches and cherries won’t die to the ground.