Autumn colors peaking in Monroe County

Some people say there are two times of year; autumn and waiting for autumn.

For them, autumn is bursting out all over with a brilliant rainbow of colors taking over the woods of Monroe County.

The countryside is awash in yellows, oranges and reds as the leaves change and this weekend might be the best time to hit the road and enjoy nature’s art show.

According to the Wisconsin Department of Natural Resources, the fall colors are now peaking in Monroe County with the hillsides holding their colors the best.

So, what causes that spectacular fall foliage?

Those colors come from three pigments tree leaves produce – chlorophyll (green); carotenoid (yellow, orange, and brown); and anthocyanin (red).

Chlorophylls and carotenoids are in leaf cells all summer long, but the chlorophyll covers the carotenoid, making leaves green in the summer and masking the yellow or orange.

Only certain trees make anthocyanins, which are produced only in autumn, and under certain conditions.

As daylight hours shorten in the fall, trees produce less and less chlorophyll, allowing the carotenoid already in the leaves to show through in a rainbow of yellows, oranges and browns.

In some years, the red fall colors seem brighter and more spectacular than in other years. That’s due to temperature and cloud cover.

Reds become more brilliant when a string of warm, sunny autumn days and cool, but not freezing, nights come in succession. The leaves can produce an abundance of sugar during the day, but cool nights prevent the sap from flowing through the leaves and down into the branches and trunk.

During those periods, trees produce anthocyanins that add their dazzling shades of red, purple and crimson to the pastoral landscape.

The carotenoid’s yellows, golds and oranges remain fairly constant from year to year since they are always present in leaves in quantities that aren’t affected by the temperatures.

However, rainfall can affect leaf colors. Falls burst of color can appear late by a few weeks following a severe drought, while periods of warm, wet weather in the fall can fade the brilliance of autumn colors.

A severe frost will kill the leaves, turning them brown and causing them to drop early. The best autumn colors occur when there has been a warm, wet spring; a summer that's not too hot or dry; and a fall with plenty of warm sunny days and cool nights.

Fall leaf colors can be used to help identify different tree species. Here are the colors associated with different trees:

• Oaks: red, brown or russet
• Hickories: golden bronze
• Dogwood: purple-red
• Birch: bright yellow
• Poplar: golden yellow
• Maple trees show a whole range of colors:
• Sugar maple: orange-red
• Black maple: glowing yellow
• Red maple: bright scarlet

Local DNR Ranger Clint Gilman encourages people to hit up one of the area state parks to see the fall foliage. Mill Bluff near Oakdale and Wildcat Mountain outside of Ontario both offer spectacular views. Visitors will need a state park sticker, which are $8 for a day pass and $28 for a season pass.

So, get out and take a drive this weekend and enjoy the colors. And let us know what your favorite route is for seeing the fall foliage. Go to the Monroe County Herald Facebook page, find the above article and post your favorite route in the comments.