Seeing Red!

When visitors to Devil’s Lake State Park are asking where and when to see “fall colors”, sometimes what they are really asking is where to see, “RED” leaves. This is because the red color doesn’t happen everywhere and in fact, it’s not even a guarantee that the red will show up at all.

The reason leaves turn yellow and orange in the fall is because the color is always there hidden beneath the green of the chlorophyll. It’s created by carotenoids in the leaves. That’s the same thing that makes carrots orange. When the chlorophyll drains away in the fall, you are left to see the actual color of the leaves.

The red color, however, takes work. This is what scientists find to be weird. Why would trees put in that extra work when the leaves are about to fall off anyway?

The Red color is created by anthocyanins which in addition to the color also act as sunscreen and antifreeze which prevent the leaves cells from freezing too quickly in the fall. The prevailing theories at the moment suggest that the red colors act as a warning to ward off pests while the trees prepare for winter. The thinking is that this defense evolved in some parts of the world but not others. The change to Red is more common in parts of North America and East Asia but less so in Europe for instance. You can read more about this idea in the links below.

So keep in mind that when visitors ask where the colors are, what they may really be looking for is the red stuff! Something we pay attention to when we put together our weekly Fall Color Reports.

Learn More

• Why More Autumn Leaves Are Red In America And Yellow In Europe: New Theory
• Why autumn leaves turn red