How to tell when tree first changes color

[JRSlawn]

Is there a web site that tells aproximent time leaves from different species will change their color? Working on school project need help asap

Thanks,

Jeff Smith
JRS Lawn & Landscape

[D Felix]

I don't know for sure if there is or not, but I doubt it.

Reason being that so many factors are involved it's not an exact science. The biggest factor is length of darkness, IIRC, not length of daylight. But you also need to take into consideration soil moisture, average ambient air temp, etc, etc. Not to mention geographic location. I know MI (LP) trees are usually about 2 weeks or so ahead of ours here in IN. And in IN, from north to south can vary by 2 weeks too....

Good luck with your project, let us know if there is anything else that we can help with.


Dan

[Coffeecraver]

I posted this eariler maybe it will help

Why do leaves change color?

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A chain reaction occurs when sunlight strikes the pigment in leaves, allowing
us to see various leaf colors throughout the year. Four broad categories of
pigment play a crucial role in autumn beauty: chlorophylls, carotenoids,
anthocyanins, and tannins.

During the spring and summer, leaves are the principal site for the
photosynthetic process that transforms carbon dioxide and water into the
carbohydrates that fuel tree growth. This food-making process takes place
in numerous cells containing chlorophyll, the pigment that gives leaves their
green color.

As days shorten and temperatures cool in autumn, the synthesis of new
chlorophyll drops off, green color disappears, and the rate of photosynthesis
declines. Trees become frugal and more efficient, pulling nutrients such as
nitrogen and phosphorus into twigs and branches for winter storage, further
enhancing the loss of chlorophyll.

Along with chlorophyll, leaves contain yellow or orange carotenoid, the same
pigment that gives carrots their familiar color. Masked for most of the year
by chlorophyll, the carotenoids reveal themselves in autumn, most noticeable
as yellows and golds in tree species such as Norway maples, Ohio buckeyes,
sycamores, birches, and hickories. For example, the golden yellows seen in
beech leaves result from the presence of tannins and carotenoid pigments.

The vivid pink, red, and purple leaves seen on maples, sassafras, sumacs,
white and scarlet oaks, and many other woody plants are formed by
reactions between various sugars and complex compounds called anthocyanins.
A mixture of red anthocyanin pigment and yellow carotene often results in
the bright orange color seen in some species of maples.


Fast Facts: Autumn Colors
Fertile soil enhances the intensity of reds in leaves.
The more light a leaf is exposed to, the more likely it is to turn red.
Weather conditions most favorable to brilliant color are warm sunny days
followed by cool nights with temperatures below 45 degrees (not to freezing
levels).
Rainy or cloudy days near "peak coloration time" will dampen the intensity
of autumn color by limiting photosynthesis.
Freezing temperatures and heavy frost can kill the brilliance of autumn color
by severely injuring leaves before pigments are fully developed.

The International Society of Arboriculture (ISA) is a nonprofit organization
supporting tree care research around the world. Headquartered in
Champaign, Ill., ISA is dedicated to the care and preservation of shade and
ornamental trees. For more information, contact a local ISA Certified
Arborist or visit www.treesaregood.com.