Quotes from 19th-century American naturalist and writer John Burroughs are some of my favorites.

He said, “I go to nature to be soothed and healed, and to have my senses put in order.”

Also: “ ... to learn something new, take the path that you took yesterday.”

Burroughs also described October as “the time of the illuminated woods.” To this, here in Minnesota, we could also add September into November.

This year with the pandemic making travel more restrictive, I have been walking the same 2-mile stretch of trail near Lake Waconia daily since March and keeping a paper record of my observations, learning much, feeling content, and enjoying the exercise.

This week I have felt the brisk fall winds, noticed the sound of crushed leaves under foot and appreciated the aroma, snacked on wild grapes, and experienced vivid autumn foliage colors. As the leaves continue falling from the various woody plants, we are reminded that there is limited time to enjoy nature’s spectacular color landscape show.

For five years beginning in 2014 the overall peak day for fall foliage colors was Oct. 14 in the metro area; last year’s peak was Oct. 17.

Throughout the spring and summer most of the foods necessary for growth of a tree, shrub or vine are made in the leaves. This food-making process takes place in the cells containing the pigment chlorophyll, which gives the leaf its green color. Chlorophyll absorbs energy from sunlight and uses it in transforming carbon dioxide and water to carbohydrates, such as sugars and starches. But in fall, because of shorter periods of daylight and cooler temperatures, the leaves stop their food-making process. The chlorophyll breaks down and the green color disappears, leaving the underlying chemicals that produce yellow and orange.

Within the same species, the degree of color may vary from tree to tree. Leaves exposed to sunlight may turn red; those in the shady part of the same tree may turn yellow.

Jim Gilbert taught and worked as a naturalist for 50 years.