Critical Temperatures for Various Fruit Crops

Posted: March 27, 2012

Tree fruit crops are in various stages of bloom and freezing temperatures are a concern. The temperature at which fruit buds are injured depends primarily on their stage of development.

As flowers swell and expand into blossoms, they become less resistant to freeze injury.  Not all blossoms on a tree are equally tender.  Resistance to freeze injury varies with trees as it does between orchards, fruit crops, and cultivars.  Buds that develop slowly tend to be more resistant.  As a result, some buds are usually killed at higher temperatures, while others are resistant at much lower temperatures.  Consideration should also be given to weather conditions preceding cold nights.  Prolonged cool weather tends to increase bud hardiness during the early stages of bud development.  Color photos of bud stages for various fruit crops and the corresponding temperatures required to kill 10 percent and 90 percent of buds have been compiled by Michigan State University.