When do the leaves change color?
Each autumn season the leaves change color; and various shades of red, yellow, orange and purple are displayed throughout the trees. The question that many ask, when will the leaves change color in my area? This can depend upon several factors and in order to have a better understanding when the leaves will change color, it is necessary to basically understand how and why they change.
Without a lot of unnecessary scientific details about chlorophyll, carotenoids and all that other stuff. We can have a basic understanding about the onset of the season change, just as Indians and natives have for thousands of years. We will look at a few conditions that vary each season which can cause the leaves to change sooner, later and with varying color intensities.
Water and Moisture
Too little moisture can cause the trees to display fall colors later in the season, and then lose their leaves early due to the drought conditions. This generally produces a brownish or yellowing effect of the leaves, without a bright colorful display.
Alternatively, too much water is associated with many cloudy overcast days. A lot of moisture can cause fungus to grow in damp cool conditions, bringing the onset of disease throughout the leaves prior to the onset of winter. This type of extreme climate can make the leaves change color a bit earlier, but the colors will not be as vibrant as in optimal conditions.
The ideal moisture conditions for brilliant fall foliage will include ample rain fall with adequate and average dry periods between the rainfall. Depending upon your location, moisture can vary from year to year, and extreme weather patterns can expedite or prolong leaf color changes.
One factor that is fairly consistent from year to year are the hours when the sun rises, and when the sun sets. Each year we spring forward and fall back changing our clocks accordingly ever since Benjamin Franklin suggested daylight savings time.
The change of the lighting schedule triggers the trees and leaves to prepare for winter by not producing a chemical that produces the green leaf color. The absence of this chemical (which typically makes leaves green) is why the leaves change to their fall colors. The earlier in the season when the days begin to get shorter, and the nights begin to be longer, you will see the leaves change earlier.
The absence of bright warm sunlight on fall days can make the leaves change earlier, but they will also not display as vibrant colors. Sunlight plays an important factor in the brilliance of the fall leaf color, so it is vital for the sun to shine nice and bright in between average rain falls, in order to display vibrant fall foliage.
Cool crisp nights without frost and freezing will help the leaves to show their best colors. However, if the temperature is too cold (freezing or below) throughout the weeks of early fall the leaves may change earlier, and will also fall from the trees earlier.
The further north in latitude such as the northern States and Canada; the cooler the nights will be, the earlier the days will end and typically the more rainfall will come. As you well know from reading the other sections, this will produce fall colors earlier in the season.
Fall Foliage maps will usually indicate a range of the fall leaf change from September to November, from the northern states to the southern states.
In conclusion there are many factors that affect the color brilliance of the fall leaf foliage and when the leaves change. With a watchful eye and diligent planning utilizing fall foliage maps and weather pattern tracking one can ideally predict when and where the most ideal fall foliage locations will be each year.
No two autumn seasons are alike and it is unlikely that you will always get it right. However, it is possible to learn from experience, and if you love the fall foliage colors it is well worth the effort to know the factors which influence when the leaves change color.