It’s December and your beautiful new oak tree still hasn’t lost its leaves yet. What does that mean? Is it dead already? Not necessarily! “This tendency for late retention of leaves, dropping them intermittently during winter, with a final leaf drop just before bud burst in the spring is called marcescence.” (University of Missouri)

“It is known that marcescence is often a juvenile trait that can be lost as some trees age. In a recent study conducted at the University of Missouri, Quercus rubra (northern red oak) trees that had multiple flushes of growth during the growing season, retained their leaves later in the year than those with few flushes. Also, leaves from the last flush on trees having the marcescent trait tended to have higher levels of chlorophyll, as well as slightly higher rates of photosynthesis than leaves from non-marcescent trees (those with early leaf drop).” (University of Missouri)

Now that you know what type of trees experience marcescence, you might wonder what causes this to happen to some trees? “Some people speculate that retained leaves may deter browsing animals, such as deer. The other reason trees might give for holding onto their leaves relates to nutrient cycling. Leaves that fall in the autumn would join others on the forest floor and begin to decay. As they decay, released nutrients could leach away and be unavailable to “feed” trees the next growing season. This might be especially important to small understory trees with smaller root systems. By holding onto their leaves, they retain and recycle their nutrients to themselves.” (University of Pennsylvania)

“Whatever the reason (if, in fact, there’s any reason at all), the sight of a small stand of young beech alongside the road; their dried, bleached, marcescent leaves highlighted by the midday sunshine, can add interest and texture to bleak, white and grey winter landscapes.” (Adirondack Almanack)

Browning Tree Service is a proud member of Indiana Arborist Association and International Society of Arboriculture, serving the West Lafayette and Lafayette, Indiana area!

Resources:

https://ipm.missouri.edu/MEG/2016/11/Marcescent_Trees_Retain_Leaves_Longer/

https://ecosystems.psu.edu/research/centers/private-forests/news/2012/winter-leaves-that-hang-on

https://www.adirondackalmanack.com/2017/11/marcescence-ecological-mystery.html