Where forest & forestry resources come together for all users!

Sponsored by the Michigan Forest Association and Michigan State University Extension

Article #27, September 1999
By Bill Cook

   Itís that time of the year once again.  Our green summer dress turns to a variety of colors before entering the quiet season of winter.  Sort of like a Latin fiesta.

   Already, the stressed and diseased trees have kicked-off speculations about the seasonís color quality.  Early color, however, is normal.  Across much of the Upper Peninsula, the summer has been wetter than usual, certainly with more rain than in 1998.  The forest has had a good growing season with plenty of stored reserves.

   Red maples in swampy areas are often the first to be noticed because of their scarlet color.  Hard to miss as youíre driving down the highway.  These harbingers of fall are exceptions, not yet the ďrealĒ thing.  Black ash normally is the first tree species to go.  They often turn a dusky yellow, but sometimes can be brilliant.  Oddly enough, itís also one of the last trees to leaf out in the spring.  A ďshort-seasonĒ tree.

   Actually, the internal clock that trees use to change colors has little to do with weather.  Itís the photoperiod.  The relative number of hours of light and dark in a day.  Now, some tree species are more, or less, opportunistic.  But in general, itís the photoperiod that affects the timing of leaf drop, not weather, or woolly bears, or bird migrations.

   However, the intensity and visual quality of the fall colors can be impacted by weather.  Stress might precipitate a more effective or quicker re-absorption of the green chlorophyll pigments.  The red, yellow, and purple pigments may stand out better, maybe for a little longer.  Frost can also have influence on the quality of fall colors, but not the timing. 

  The biggest portion of our hardwood, or broad-leaf, forests consist of maples, aspens, and birches.  The crimson and gold of maples we all know about and that pretty much beats the pants off color changes in other parts of the country.  Our aspens also turn a fantastic yellow color, with the right weather conditions.  Birch are much the same way.  A bright yellow pure paper birch stand, with snow-white bark, can be quite a visual experience. 

   But, let us not forget the softwoods, or evergreens.  Although they do retain needles year-round, they donít retain them all.  The older needles, nearer to the trunk, fall off every year.  The only exception to this is the glorious tamarack.  It doesnít just lose all its needles each fall, but it does it with a blazing aurora of gold! 

   I think tamarack can provide the very finest fall show of all, under the right conditions.  When the sun is low in the west shining on a tamarack grove, and heavy, dark clouds are on the eastern horizon, the scene is enough to stop me in my tracks.  Once in northern Minnesota, I nearly hit a moose while viewing such a display.  I have since learned to pull over to view a particularly gorgeous view.  And often do.  I hope that you, too, enjoy the fall this year.

-  30  -

Bill Cook is an MSU Extension forester providing educational programming for the entire Upper Peninsula. His office is located at the MSU Upper Peninsula Tree Improvement Center near Escanaba. The Center is the headquarters for three MSU Forestry properties in the U.P., with a combined area of about 8,000 acres. He can be reached at cookwi@msu.edu or 906-786-1575.

Prepared by Bill Cook, Forester/Biologist, Michigan State University Extension, 6005 J Road, Escanaba, MI  49829
906-786-1575 (voice),  906-786-9370 (fax),  e-mail:  cookwi@msu.edu

Use / reprinting of these articles is encouraged. Please notify Bill Cook.
By-line should read "Bill Cook, MSU Extension" Please use the article trailer whenever possible.

Michigan State University is an affirmative action equal opportunity institution.  The U.S. Department of Agriculture prohibits discrimination on the basis of race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital status or family status.   (Not all prohibited bases apply to all programs.)

This website is maintained by Bill Cook, Michigan State University Extension Forest in the Upper Peninsula.  Comments, questions, and suggestions are gratefully accepted. 
Last update of this page was 5 November, 2018




This site is hosted by School of Forest Resources and Environmental Science at Michigan Technological University.

Michigan Tech