Fall leaves' true colors will shine through soon

October 19, 2002|By ROB KASPER

THE LEAVES will fall from the trees. You learned it here first, at foliage central, a veritable compost pile of information on dead and dying vegetation.

Here is another important seasonal bulletin. Once the leaves hit the ground, you are going to have to get rid of them - unless you live in the sticks. Recently, some longtime distinctions between places that are "distant suburbs" and those that are authentically rural have become blurred. But when it comes to dealing with dead leaves, the line of demarcation is still strong.

If you can let your dying leaves lie and not get harassed, you live in the country. If not, you are living a citified lifestyle, at least on the foliage front.

(In prior years, another mark of living in the sticks was being able to burn leaves out back of your place without getting thrown in the hoosegow. But thanks to this year's drought, a statewide ban on burning leaves and other forms of open burning was imposed in August. The ban might be reviewed if rainfall increases, Monte Mitchell of the state's fire management office said late this week.) Speaking of fire, the burning question in fall foliage these days is whether the summer's drought will affect fall color. The answer: You betcha it will! It will either make it worse or better, depending on whom you believe.

On one side is the drought-is-a-bummer faction. It maintains that our trees, exhausted after working this summer without adequate rainfall, will shut down earlier than normal this fall. This fall's leaf season, this faction predicts, will be short. Before you can say "mandatory water restrictions," the leaves will have taken a dive. Bummer.

On the other hand, some leaf peepers maintain that a struggle, such as the summer drought, produces beauty, even deep purple splendor. They say that dry, sunny weather increases the sugar concentration in tree sap and that, in turn, increases the display power of anthocyanins, a class of pigments found in leaves that can produce red, blue, purple and magenta colors. So the brightest autumn colors occur, they say, when dry, sunny days are followed by cool, dry nights.

One day this week, I tossed the speculation about the good leaf year/bad leaf year scenarios in the lap of Mike Galvin, supervisor of urban and community forests for Maryland's Department of Natural Resources. He said, in effect, either could happen.

One factor favoring a potentially quick leaf drop is the trees' habit of protecting their core operations by retaining water and shedding leaves, Galvin said. Another is that a sharp drop in nighttime temperatures, similar to that we experienced this week, could encourage Maryland leaves to behave like vendors at Ocean City and drop out of sight as soon as the first cold winds blow. So far, he said, it is too early to tell.

Galvin said he also saw some merit in the notion that this fall's leaf season could be a deep purple delight. It depends, he said, on those anthocyanins. In some trees, these pigments vie with another group of pigments, the carotenoids, over which group gets to show off more of their color in the leaves. Carotenoids, which produce yellow, brown and orange colors, are tough and make their presence known every fall as the green hues or chlorophyll in the leaves fades.

Anthocyanins, on the other hand, are the divas of fall color. They put on an occasional performance, and when they do they require that tree leaves have a certain amount of water and a certain amount of sugars, and that the sunlight be just so, all at specific times in the color-changing process. If all goes well, the result can be spectacular.

One indicator of what the anothocycanins might be up to, he said, is to check out the black gum trees. This fall the leaves of black gum trees in central Maryland have already begun to turn and are showing "deep fiery red" hue, he said. This is a hint, Galvin said, that Maryland leaf season could be "brilliant, but brief."

We here at foliage central take no position on whether this fall is going to be a bummer or a knockout. That is because we don't have a clue about chemistry. We just read the explanations about the chemistry of autumn colors on various Web sites and try to comprehend it. When the text turns to "endothermic transformation" and formulas like Cx(H2 0) y start to appear, our palms start to sweat, and we change the conversation to what's new in leaf removal.

And speaking of what's new, the rake is making a comeback. Of the three ways to lose your leaves - blow them away, suck them up or rake them into piles - raking has long been considered the old-school approach. But lately, as leaf blowers and suckers got more powerful and neighbors got more annoyed by the noise, these machines have dropped a notch or two in social acceptance. Communities scattered throughout North America have passed laws restricting leaf-blower use. And in some "greenie" neighborhoods, the growl of a leaf blower is about as welcome as a Jet Ski slicing through a cove of sailboats.

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