DISCUSSION: Spring is important for fruit trees. Spring welcomes trees into a warmer season in which they begin to bloom. What you may not realize, however, is that colder weather is necessary for fruit trees to survive.
Fruit grown on trees, such as apples, cherries, and peaches, account for $4 billion annually in the U.S. Fruit trees often begin blossoming in the spring, but they also rely on winter dormancy in order to fruit properly. The rest period that fruit trees rely on, also known as a cooling period, allows trees to properly chill before spring. The ideal temperature for most trees is 45 degrees Fahrenheit, which is within the 35 to 50 degrees threshold. When temperatures fall to or below freezing, there is no benefit to the trees.
While most trees thrive in winter dormancy at 45 degrees Fahrenheit, different fruits require varying amounts of hours at these temperatures. Peach and apple trees both require roughly anywhere between 400 to 1100 hours. Cherry trees require the longest cooling period, with a needed minimum of 1,000 hours to thrive. This is part of the reason why cherry trees are located in cooler climates, such as Michigan and Washington. Peaches are found in states with milder climates like California and Georgia.
Fruits are unable to bud unless they have been provided a long enough cooling period. Once the cooling period has ended, the fruit trees will bud. Whether trees bud on time, early, or late is all dependent on whether the tree has met not only its warming period but its cooling period requirements. The length of the cooling period and warming periods, or the maximum amount of days above 40 degrees Fahrenheit, will determine when the trees bud.
Climate change, however, is spelling trouble for the fruit trees. Shorter, milder winters result in earlier springs. With fruit trees not being allowed to properly complete a cooling period, the areas where certain fruits will be able to grow will change and shift. Areas that depend on fruit crops heavily for local or regional economy will suffer from decreased yields. A changing climate also spells trouble for pollinating animals, whose migratory patterns are dependent on when certain seasons change.
February 2017 brought a perfect example of the changing climate’s effects on fruit trees. A record-warm February allowed apple and peach trees to blossom early in the Southeast. However, a freeze in March caused damage to those same crops. In addition to other fruits, the damage to agriculture in the Southeast ended up being $1 billion during Winter 2017. Unfortunately, crop losses are just one problem that will result from a changing climate.
To learn more about other interesting stories related to global climate issues, be sure to click here!
©2018 Weather Forecaster Jacob Dolinger