My reachable apple tree is blooming. What do I do?
Washington County Oregon
Although apple trees normally bloom in the spring, under certain weather conditions you may also see a few blossoms in the fall. (I'm assuming your apple tree is not in full bloom, but has blossoms on a few branches.) The needed conditions are usually a start and stop pattern in tree growth and development. This pattern is often caused by unusual weather conditions; higher than normal rain in early summer followed by hot dry weather later in the summer. We had a wetter and cooler than normal June, followed by hot dry weather in July and August.
Fruit trees set buds for flowers in summer, and the buds develop at slightly different rates. If we experience hot, dry conditions and then conditions cool and we get some fall rains, the tree can send signals to certain more developed flower buds to break out of dormancy. Most of the apple blossoms are not developed enough to actually bloom, leaving them to develop more and bloom at the normal time in spring.
This should not cause any problems with flowering or fruit development next spring. Only a few blossoms are developed sufficiently to bloom, leaving the vast majority to bloom in the spring.
To prevent this from happening give your apple tree some moisture during hot dry periods in summer. A good soaking every couple of weeks during hot dry weather will get moisture down to the roots and keep the conditions more consistent for the tree. This article has a more detailed explanation of this event, Why are my Apples Blooming in the Fall? https://www.canr.msu.edu/news/why_are_my_apples_blooming_in_fall