The Berkshires Blog

Foliage Report #1 – The Berkshire Leaf Chief

Although it is good to be alive on this most beautiful planet regardless of the season, residents and visitors alike are annually stunned by the scarlet, red, orange, brown, tan and occasional deep purple that make up this area’s fall foliage, may it be preserved.

Berkshire County has had a cool and wet summer—delightful sleeping temperatures but some damp play days. Trees should be relatively healthy. In general, we will have a striking, extended leaf season, its height beginning around Columbus Day. While the immediate weather may affect the intensity of the color, probably it has a greater effect the viewer’s perception. So—bottom line—pick nice days to peep; the leaves will pretty much do their part.

Here is the chemistry. As summer daylight hours shorten and darkness lengthens, a hormone composed of a sugar-like substance travels down the stems of deciduous leaves to the point where they attach to the branches. In these parts, some leaves start to turn as the daylight reduces to 14 hours, in mid-August. The hormone stiffens the cells, creating a ring that tightens around the stem, preventing the passage of water to the leaves. (That ring is visible in the thickness at the end of a downed leaf stem.) Without water the chlorophyll cannot survive, so leaves stop manufacturing food and the green color that masks the yellow pigment of the leaves. In some species the hormone generates red, but fall is primarily the time of unmasking rather than of adding color to leaves. While cold nights assist the deciduous miracle, the timing depends primarily on day length.

The process takes place only in deciduous trees, those that drop their leaves all at once, as opposed to evergreens that have only partial needle drops at any one time. In essence, the leaves are choked to death, yet with the golden promise that the trees themselves don’t die and will sprout new leaves profusely in the spring. Visitors and residents have the good fortune to observe the annual spectacle in Berkshire County where the coming together of forests dominated by oak in the south and sugar maple to the north gives us maximum variety. We are in a transition area between forest types, so we get to enjoy both.

Come and enjoy the early changes at the FreshGrass Festival at MASS MoCA or on one of Housatonic Heritage’s Heritage Walks. Both are great ways to be outside and enjoy the Berkshire foliage.