What is Marcescence? See The Phenomenon in These 3 NYC Trees!

On your winter stroll in your local park or natural area, you may have noticed that a few trees are still hanging on to their leaves. This isn’t by random chance—some deciduous trees retain their autumn leaves in a process called marcescence. 

For most deciduous trees, when autumn arrives, an “abscission layer” forms at the base of a leaf petiole. This is basically a group of cells that soften, allowing leaves to detach. This helps the tree conserve energy over the winter.

But some trees like to do things a little differently and wait to drop their leaves until spring! The exact reason why marcescence occurs in some species hasn’t been proven, but scientists have a few theories!

What might cause marcescence?

• Trees retain their leaves to protect their tree buds from animals foraging for food 
• Holding onto leaves can provide trees a fresh layer of mulch when they finally fall in the spring

3 NYC trees with marcescence

1. American beech

2. White oak

3. Pin Oak

Grow your leaf expertise even more! Check out our blog post on how to identify fall leaves.