“It was you that set up all the boundaries of the earth; summer and winter—you yourself formed them.”—Psalm 74:17.
And so’s autumn and spring.
I arrived in Vienna on October 14th of 2002. It was already autumn, the smell of dried leaves and the blow of cold wind were such welcomely feeling. Upto this day, when autumn comes, I remember the thoughts that I had upon seeing the orange-yellowish landscape for the first time.

So how or more appropriately, why does the green leaves of summer turns to yellow, orange or red during autumn? We know that leaves have the green pigment chlorophyll used in the production of plant food (glucose). Leaves also has the yellow (carotenoid pigment) and red (anthocyanin pigments) but is not seen much because they are covered up by chlorophyll. The leaves know that it is autumn when the days become shorter and shorter, since ‘photosynthesis,’ the process where plant makes food happens with the help of light.

As animals hibernate during winter, so does some plants and trees in the same way. Animals store fats and sleep off during winter while plant leaves store glucose and shut down their food making factories. The chlorophyll are then gone and now the yellow and red pigments are revealed, naturally when they combine, orange is produced.

As for maple trees, persimmons and other red colored leaves, the leftover foods plus the (occasional) sunlight and cool breeze of autumn makes this wonderful color comes out.

Looking closely at nature, one sees the invisible hands of Jehovah at work. I myself am awed on how he set all the pieces of creation even preserving them, giving them sunlight, rain and rest. Truly, the inspired writer summarized it all.
“Jehovah himself in wisdom founded the earth. He solidly fixed the heavens in discernment. By his knowledge the watery deeps themselves were split apart, and the cloudy skies keep dripping down light rain.” -Proverbs 3:19-20