“Anyone who thinks fallen leaves are dead has never seen them dancing on a windy day.”
~ Shira Tamir

Earlier in the week winds came howling out of the local mountain canyons. Temperatures jumped 20 degrees warmer within a day. We sat in our neighbor’s front yard (masked and six feet apart). While colorful leaves swirled to the ground our dogs wrestled and raced among the Christmas lawn decorations.

We’ve heard the Jack Frost story involving his coloring of fall leaves and nipping at toes. As it seems to grow cooler with each autumn day, we can almost imagine his nightly visits with palette and paintbrushes in hand. But scientists tell us that while it has something to do with warm days and nightly frost, there’s much more to it. Actually, to understand how fall colors appear let’s look back to the tree in mid-summer.

When the leaves flutter in the summer breezes, with bright sunshine overhead, tree leaves produce a substance called chlorophyll. Acting as a color pigment in the tiny cells of leaves, the heavily foliaged trees of summer turn intense and varied shades of green. Think of the green chlorophyll as a Halloween mask. Underneath the green color of the chlorophyll other colors lie hidden from view.

According to legend, every autumn Jack Frost paints the summer leaves in tones of orange, yellow, red and purple; landscapes receive the touch of an artist.

Actually, frost has little to do with fall leaf color. There’s science behind the beauty.

Changing leaf color is a chemical process activated by the shorter days and cooler temperatures of fall. Jack Frost’s color palette is empirically represented by chlorophyll for green, carotenoids and xanthophyll for yellows, and anthocyanin for purples and reds. Chlorophyll is used by plants to make sugar from sunlight.

The shorter and cooler days of autumn slow down a plant’s life processes. Chlorophyll production slows and ultimately disappears. Yellow pigments are unveiled first, with purple the last. A view over the Crescenta Valley reveals such, reminiscent of grandma’s quilt.

Today, Thursday, and tomorrow temperatures are expected to drop, only to rise again over the weekend. Add some random wind and clouds to the mix. Looking ahead, next Wednesday there’s a chance of sprinkles. Even further out – 16 days – no rain is in the forecast. Sleigh landings on the 25th will be onto a carpet of fallen leaves and not snow!