by Shane Harris, Regional Extension Agent
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Published  in The Outlook and The Dadeville Record

Still Waiting on Fall Colors to Appear

By mid October, one would expect it to feel and look like fall.  However, that is not the case this year.  The cool mornings are quite nice but these 80 °F plus afternoons are way too warm and humid. Not only are the unusual warm days just plain hot, it is keeping many of the trees’ foliage from displaying fall colors. Some leaves are starting to show signs of turning here and there but most are waiting for cooler temperatures. And what’s even more frustrating is that the same problem exists further north up in the mountains of Tennessee, Georgia, and North Carolina. So just how I am suppose to plan a trip to the mountains with the sole purpose to SEE the wonderful fall color when it won’t change?  Do nothing I guess but wait, wait, and wait some more.

From all the fall foliage reports I have gathered in the last two weeks, which are few and far between I might add, the fall show of color is going to be much later this year. If my memory serves me right, the third week of October has traditionally been the best time to view fall foliage in the mountains. In central Alabama, we typically do not see a significant amount of color due to our climate and elevation; it is just not cool enough.  However, most trees that do display nice color on average will peak in early to mid November.

Three factors influence autumn leaf color - leaf pigments, length of night, and weather, but not quite in the way we think. The timing of color change and leaf fall are primarily regulated by the calendar, that is, the increasing length of night. None of the other environmental influences - temperature, rainfall, food supply, etc., are as unvarying as the steadily increasing length of night during autumn. As days grow shorter, and nights grow longer and cooler, biochemical processes in the leaf begin to paint the landscape with Nature's autumn palette.

The amount and brilliance of the colors that develop in any particular autumn season are related to weather conditions that occur before and during the time the chlorophyll in the leaves is dwindling. Temperature and moisture are the main influences.

A succession of warm, sunny days and cool, crisp but not freezing nights seems to bring about the most spectacular color displays. During these days, lots of sugars are produced in the leaf but the cool nights and the gradual closing of veins going into the leaf prevent these sugars from moving out. These conditions, lots of sugar and lots of light, spur production of the brilliant anthocyanin pigments, which tint reds, purples, and crimson. Because carotenoids are always present in leaves, the yellow and gold colors remain fairly constant from year to year.

The amount of moisture in the soil also affects autumn colors. Like the weather, soil moisture varies greatly from year to year. The countless combinations of these two highly variable factors assure that no two autumns can be exactly alike. A late spring, or a severe summer drought, can delay the onset of fall color by a few weeks. A warm period during fall will also lower the intensity of autumn colors. A warm wet spring, favorable summer weather, and warm sunny fall days with cool nights should produce the most brilliant autumn colors.  

Grape Growing Workshop
If you enjoy growing and eating grapes then you might want to attend the Grape Growing Workshop in Birmingham on October 25, 2005.  Stan Roark, Regional Extension Agent in Randolph County, has put together a great program on growing and using grapes, both muscadines and bunch grapes.  The workshop will discuss establishing and managing a vineyard, varieties of grapes for Alabama, pest management, and the economic impacts of growing grapes in Alabama.  Whether you’re growing grapes for personal consumption or would like to learn more about processing grapes into jams, juices, jellies, or wine, this seminar is for you.

To find out more about growing grapes in Alabama or attend the Grape Growing Workshop on Tuesday, October 25, 2005, in Birmingham, contact your local county Extension office.  This program will be held from 8:30 a.m. to 4 p.m. at the Birmingham Botanical Gardens. There is a charge of $10 if you register before October 18; the charge is $15 thereafter and at the door. You can also reach Stan Roark at (256) 357-2841 or Sallie Lee at (205) 879-6964 – ext. 11 for more information and a registration form.

For more information, contact the Tallapoosa County Extension Office at 256-825-1050.