Fall Foliage

Kay Hinkle
Adams County Master Gardener

As you read this article, the brilliant colors of autumn may be fading already. The peak of color is just past here in South Central Pennsylvania. The trees that are content most of the year to stay in the background have come forth with their brilliance and are on their way to being a backdrop again.

Many "leaf-peepers" (those who travel to see fall foliage) travel to the New England States to see the colors of autumn. Did you know that you could do the same in the Western part of the United States in the area from Utah north to the Canadian border and parts of Northern California, Oregon and Washington State?

Fall foliage tours are big business; hitting the right time for a visit is a bit of a challenge since Mother Nature doesn't work on calendar days. As daylight hours lessen and the nights grow cold, a glorious show of colors begins to unfold. This transformation occurs when conditions are just right, and as conditions vary from year to year, so does the peak season for viewing fall foliage.

What is it that causes the leaves to turn colors? As we get into shorter days and longer nights, a number of hormonal changes take place in the leaves. The connection between the leaf and stem changes, choking the movement of nutrients and moisture to the leaves. The green color fades and exposes yellow underneath.

The rest of the hues in the palette of colors we see in fall foliage are encouraged by the production of sugars. These sugars are not in the leaf when it forms, but are generated in the late summer into fall. Shades of brilliant orange and deep reds result.

Showers, hot days and dry spells during the summer determine how long a leaf will remain green. We saw many leaves dry up and turn brown long before autumn locally. Many of those that remained on the tree have turned to brilliant color, however.

You may have noticed that the color red has been prevalent in our woodland palette this year. That is probably the result of the stresses of drought in our area. A research plant physiologist with the U.S. Department of Agriculture's Forest Service has studied the impact of stresses like lack of rain on red leaf pigment for several years. His studies

indicate that in drought-stricken years, "leaf peepers" will see more red, and the color will show earlier. All in all, the color of fall foliage tends to be more brilliant as the result of dry summer months.

Red makes an interesting study because it varies from year to year. Green and yellow pigments are always present in leaves and don't change dramatically from year to year. Essentially, trees create red as the weather warrants.

In choosing trees to enhance your autumn landscape, consider the magnificent fall color of maples that range from reds to yellows: Silver maples show yellow in the fall, sugar maples show great variability, and the maple cultivar 'Autumn Flame' or 'Red Sunset' consistently tend to show a good red color. Choose a member of the birch family for yellow hues, flowering dogwoods for reds, and a member of the oak family for russet to yellow-brown.

Whether you are an avid "leaf peeper" or just one who enjoys watching the change of seasons, another of Mother Nature's miracles has just unfolded before your very eyes.

And soon another miracle in the first falling snowflakes, with no two alike. followed a few months later by a burst of new life as evidenced by the delicate new buds of spring. And followed, of course, by an abundance of produce from the vegetable garden and summer rains (or drought) .. followed by falling leaves. as Mother Nature's cycle of life continues!

Finally, a list of gardening tips for November and December: - After a month of cold temperatures, pot your chives and bring indoors. Cut back and water. - Think about lining your windowsills with aluminum foil. The foil reflects light and provides extra light for houseplants that spend the winter on a windowsill. - Cover your garden tools with a light coating of oil. - Continue to plant bulbs as long as the ground isn't frozen. - Mulch your perennial bed after the ground is frozen. - Water the birds in winter. Use a durable plastic flowerpot saucer to hold water.

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