The fall season reminds me of the quote from Michelangelo: “Every block of stone has a statue inside it; it is the task of the sculptor to discover it.” The leaves of trees and shrubs have had their wonderful riots of color all along. It just takes the triggers of autumn’s changing light, temperatures, and moisture to finally reveal them.
As we all learned back in elementary school, chlorophyll is the chemical in plant leaf cells necessary for photosynthesis, the process that enables plants to convert the energy from sunlight to manufacture carbohydrates. Chlorophyll also give leaves their green coloring.
During the spring and summer, chlorophyll is in constant and plentiful supply, as the leaves of deciduous plants are busy producing the carbohydrates necessary for growth (and to store away for the winter dormant period.)
In the fall, as daylight is in increasingly shorter supply and the temperatures cool, the production of chlorophyll slows and then stops, and its green color disappears. That allows the other natural pigments present in the leaf cells to finally become visible — the yellow pigments known as xanthophylls, and the orange pigments called carotenoids. Autumn conditions also trigger the manufacture of anthocyanins from the sugars that are trapped in the leaf; this is where the leaves’ red and purple pigments come from.
It is particularly the production of anthocyanins which give the color depth and brilliance so many leaf-peepers treasure. Warm, sunny days mixed with cool, above-freezing nights seem to favor the bright reds and purples of anthocyanin formation, while an early frost will weaken those hues.
Best Times to Peep? Peak Fall Foliage Predictions
Since warmer-than-average temps are predicted for September thru November in much of the country, the fall leaf colors are expected to last a bit longer than usual. The Farmer’s Almanac has predicted the following timing for 2017 peak fall colors in our SavATree customer areas (and we’ve also imbedded a state- or region-specific links to fall foliage reports or forecasts):
Delaware: Oct. 19-Nov. 4
Maryland/Virginia/D.C.: (Inland) Oct. 12-28; (Coastal) Oct. 19-Nov. 4
New Jersey: (Inland) Oct. 12-28; (Coastal) Oct. 19-Nov. 4
New York: Sept. 28-Oct. 28 (depending on elevation and distance from the coast)
North Carolina: (Inland) Oct. 12-28; (Coastal) Oct. 19-Nov. 4
Pennsylvania: Oct. 5-21
Illinois: (Northern) Oct. 5-21; (Southern) Oct. 12-28
Indiana: (Northern) Oct. 5-21; (Southern) Oct. 12-28
Michigan: (Northern) Oct. 1-17; (Southern) Oct. 5-21
Minnesota: (Northern) Oct. 1-17; (Southern) Oct. 5-21
Ohio: Oct. 5-21
Wisconsin: Oct. 5-14
Connecticut: Oct. 12-28
New Hampshire: (Inland) Sept. 28-Oct. 9; (Coastal) Oct. 5-21
Maine: (Inland) Oct. 1-17; (Coastal) Oct. 5-21
Massachusetts: (Inland) Oct. 5-21; (Coastal) Oct. 12-28
Rhode Island: Oct. 12-28
Vermont: (Northern) Sept. 24-Oct. 10; (Southern) Oct. 5-14
Rocky Mountain & Wasatch Region