Why oak trees often hang on to their leaves
While most trees are barren of leaves this time of the year, many oaks are still hanging on tight.
Frances Main, a forester with the Missouri Department of Conservation, explains that the basic answer is genetics. Only certain species of oaks tend to keep their leaves all winter until the new spring leaves push them off. Post oak and pin oak are the two prime examples because each of them are adapted to the extremes in the oaks’ growing conditions – dry to wet.
An exception can be when strong winds can literally blow the dying leaves from the trees. Late 2014 was unusual for most species of trees because of a very cold spell in early November. It may not have seemed like it when you were raking and mulching fall leaves, but many of them were freeze-dried on trees before they had completed their drop cycle. Likely, that means more leaving collecting to be done this spring, especially in those irksome corners that seem to have a “leaf magnet”
One theory is that trees hold onto their leaves for nutrient cycling. When the new buds push dead leaves off in spring, the leaves fall to the forest floor and provide nutrients at a time when the tree is about to start an active growth period.