October 2008

As the days grow shorter and the weather becomes cooler, a colorful palette of leaves will blanket the Leonard J. Buck Garden, eliciting wonder and delight. The annual change in color from summer greens to brilliant hues of fall has begun.

The green leaves of summer owe their color to the green pigment chlorophyll. Chlorophyll enables leaves to capture light and chemically create sugar, a process known as photosynthesis. These sugars are then translocated throughout the plant to supply energy.

In addition to chlorophyll, leaves also contain large amounts of the yellow pigments carotene and xanthophylls. We don’t see these lighter colors in the summer because the dark green of the more abundant chlorophyll masks the lighter yellow color.

When the weather becomes cooler, chlorophyll begins to breaks down, thus allowing the more stable yellow pigments to become visible. Some trees such as sweet gum and red oak, New Jersey’s state tree, have red pigments called anthocyanins. As the chlorophyll in these leaves break down they turn orange, red or maroon depending on the mixture of red and yellow pigments.

Some trees such as oaks have high tannin content; the leaves will turn brown as the chlorophyll breaks down.

It is the combination of the various amounts of these different pigments in the leaves of tree species that gives our eastern hardwood forests its array of spectacular fall color. Some trees may exhibit a combination of green, yellow, red or brown at any one time, but most species of woody plants have a general characteristic fall leaf color.

Birches and tulip poplar trees are typically a clear yellow, beech tree a bronzy yellow, the hickories a golden yellow. Dogwood, sourwood, sumac, and sweetgum are usually various shades of red.

Under certain conditions, a yellow leaf may occur in predominately red-leaved species but yellow-leaved species do not have the chemistry to produce red leaves. If having a maple that turns red in the fall is important to you, pick your tree out in the fall when you can see the fall color.

One doesn’t have to plan a big adventure to see fall color; an enjoyable fall foliage trip is right around the corner in a nearby park.

For all who enjoy fall color, the following is a list of places to see fall foliage in the Garden State: