Red oak in September:
Red oak in October:
Red oak today:
See all the dead leaves still clinging to its branches? This is called marcescence. A lot of oaks and beeches, especially younger ones (and especially on lower branches, as seen here), hang onto the past season’s old dead leaves throughout the winter. The dead leaves finally drop off in the spring when new ones grow in their place. No one is quite sure why some trees do this, but there are a few theories – well, a lot of theories.
- Dropping dead leaves at the beginning of spring could provide a burst of fertilizer to start off the growing season as the leaves decompose.
- Keeping the leaves in the winter could help trap more snow around the bases of the trees, giving them extra moisture when the snow melts in the spring.
- The dead leaves could even provide some protection from cold and frost for the tree’s buds or even deter browsing by herbivores.
For more information, check out this great article on marcescence by a professional forester in Vermont. Are any trees marcescing (did I just make up a word?) in your area?