Why Are There Dead Brown Leaves On Some Trees?

Trees with dead leaves

As I’ve been driving around our incredibly snowless landscape this winter (not that I’m complaining, mind you) it occurred to me that the predominant color was the brown–from leaves remaining on some trees.

There’s actually a term for this phenomenon–it’s called marcescence, although that technically is the term for anything “dead” that remains on a plant: dead flower buds, dead flower heads, dead grass leaves that we leave remaining to rustle through the winter–you get the gist.

The dead leaves on deciduous trees remain there for some time. Usually at my house, they remain until early spring, when new growth pushes them off, although I have noticed that this year that’ they’re already gone from our yard. We had a very early heavy wet snow and that may have been the culprit in knocking them down.

Maple with dead leaves

As this maple in a neighbor’s yard shows, however, not all the leaves have come down. And of course there are still plenty of rose hips, hydrangea heads, and ornamental grasses–not to mention the evergreens and the holiday decorations–to brighten the winter until the inevitable snows come.

It is suspected that the leaves remain–when they do–to protect the delicate leaf bud beneath–through the winter. In my part of the country, this happens with some maples, oaks and alders. In other parts of the country, other trees may hold their leaves too.

I have also seen it posited that the leaves remain to protect the plants from animal browsing but I can tell you from personal experience with deer that it doesn’t help so that can’t be the reason. I know in the case of my hydrangeas, which are very hardy at the roots but marginally hardy at the leaves and flower buds, I’m sure the leaves remain to protect those tender buds!

So there you have it: more than you ever wanted to know about dead winter leaves!

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4 thoughts on “Why Are There Dead Brown Leaves On Some Trees?

  1. Hi Roberta,
    Yes, when new growth occurs, the old leaves generally fall from all species. The new growth will push it off. Think of how horrible it would look if the old leaves didn’t fall, right?

    Thanks for reading and commenting. Happy New Year.

    Karla

    • Hi Lottie,
      I fear I was unclear in my answer to Roberta & that’s what’s led you to question my veracity.

      The old leaves are are pushed out by new growth, as I said. But if you go back to my post, you’ll see that I state that the leaves remain to protect the tender bud of new growth underneath. Once the new leaf begins to unfurl, they serve no purpose.

      I hope that helps to clarify my answer for you.

      Karla

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