Fruit trees requires a specific amount of cold temperatures to grow correct, and this amount of cold is measured in chill hour. Chill hours is the total number of hours that a fruit tree spends in a dormant state below a specific temperature threshold. A fruit tree need these chill hour because the chill hours act as a biological signal to the fruit tree that it is safe to wake up and begin growing.
If a fruit tree doesnt receive enough chill hours, the fruit tree will not function proper, and the fruit tree will not produce edible fruit. Different varieties of fruit tree have different requirement for chill hours, and these requirements vary significant between species. For example, a cherry tree may require more than one thousand chill hour to function properly, but a peach tree may require very few chill hour to function properly.
Choose Fruit Trees by Chill Hours
Many people makes the mistake of choosing a fruit tree based off the taste of the fruit, but you must choose a fruit tree based on the chill hour requirement of the fruit tree. If you plant a high chill fruit tree in a warm climate, the high-chill fruit tree will not receive enough chill hours, and the high-chill fruit tree will produce a stunted or uneven harvest. Conversely, if you plant a low-chill fruit tree in a cold climate, the low-chill fruit tree may break dormancy too early, and a late spring freeze may destroy the low-chill fruit tree.
You must consider the local climate when you are selecting a fruit tree, and you must ensure that the local climate provide enough chill hours for the specific fruit tree. You should also consider the historical average of your local climate because some winters are milder than other winters. If a winter is milder than average, the total number of chill hours in that winter may be lower than the historical average, and a lower number of chill hours can prevent the fruit tree from blooming correct.
Additionally, you must consider the elevation of your planting location because elevation affect the temperature of the environment. For example, a fruit tree planted in a mountain orchard may receive more chill hours than a fruit tree planted in a valley, because mountain orchards are typically colder than valleys. The goal of selecting a fruit tree is to match the fruit tree to the available chill hours in your environment.
You want to find a fruit tree that receive enough chill hours to trigger a massive bloom, but you also want to ensure the fruit tree does not remain in a state of permanent dormancy. If you select a fruit tree that fit within the historical chill hour average of your location, the fruit tree will have a higher probability of producing a successful harvest. You must account for the chill hours, because the chill hours is the primary factor that determines if a fruit tree will produce fruit.