Why is the grass green?

One day you go for a walk with your dog, Fluffy. Right as Fluffy is about to do her business, you look down and wonder “Why is the grass green?” While Fluffy looks back at you confused, unable to answer your question, we can certainly try to explain it!

The reason why grass and almost every other plant is green is thanks to the interaction between sunlight and a chemical compound called chlorophyll. Sunlight looks white to us, but this is because it is made of all the different colors of the color spectrum. It is like a rainbow, but with all the colors stacked on top of each other. Sunlight is necessary for plants to survive, and chlorophyll helps plants and grass capture sunlight! Chlorophyll only captures certain wavelengths (colors) of the visible light spectrum, specifically red and blue wavelengths. The green wavelength is not captured, on the contrary, it is reflected (like a mirror) and that reflection is what makes our pretty eyes see grass and plants of a beautiful green color.

Next time you take Fluffy on a walk ask yourself, "how different would the world look if chlorophyll reflected red or blue instead of green?" It would certainly be something out of this world!

By Dr. Karen Ventura