Wild Ideas: “The autumn leaves drift by the window”  

Just after the autumnal equinox, I came back from the Outer Banks to a dry, dusty Rappahannock County.

This time of year, I often think of the wonderful, if somewhat melancholy, lyrics by Johnny Mercer to “Autumn Leaves,” a jazz standard. The lyrics of the original French song, “Les Feuilles Mortes” (“The Dead Leaves”), written by poet Jacques Prévert, were much darker, with no “leaves of red and gold,” as Mercer described them.

Dry leaves at my house were cascading down from the sky rather than “drifting,” blanketing the forest trails and crunching underfoot. And they were leaves of brown and pale yellow — more like those Prévert had in mind rather than Mercer’s autumn leaves.

By early October, the leaves of some woody plants were starting to show fall color, although in some cases duller than usual, while other leaves just died and fell off, littering forest paths. (Clockwise from left: Virginia creeper, a forest path in the Blue Ridge Mountains, a sycamore leaf and sassafras leaves.) By Pam Owen

The vibrant hues of red, gold and purple that dominate Virginia’s usually spectacular fall foliage  are produced by woody plants — trees, shrubs and vines. Leaves are the plants’ food factory, and when they turn color in autumn, it is a sign that the factory is shutting down for the year. The color comes from the breakdown of chlorophylls and then sugar as the plant draws nutrients down into its roots for winter.

The hue and intensity of the leaf color depends on the timing and level of three factors: temperature, sunlight and soil moisture. The most vivid foliage occurs when the growing season featured plenty of moisture and is followed by an autumn that is dry, sunny and cool but without frost. Drought can cause leaves to fall off before they change color.

According to the National Oceanic and Atmospheric Administration, rainfall in Virginia overall was “much above average” this spring but “below average” this summer. And spring temperatures were “much above average,” while summer temps were “above average.” Basically, summer was hot and dry, and that weather continued into early October. But does this mean we’re experiencing a drought? If so, how will this affect Virginia’s famous fall foliage, an important driver of the tourist economy throughout much of Virginia?

For drought monitoring purposes, the Virginia Department of Environmental Quality divides the commonwealth into 14 regions, with Rappahannock being in the Northern Piedmont region, along with Culpeper, Greene, Louisa, Madison, Orange, Spotsylvania and Stafford counties, and the city of Fredericksburg. In determining the threat of drought, DEQ monitors four water parameters: precipitation, groundwater, reservoir water and flow. Stages of drought run from “normal” (no perceived drought threat) to “watch” (“prepare for the onset of a drought event”), “warning” (“onset of a significant drought event is imminent”) and “emergency” (“significant drought event” is occurring in which “all users and non-essential uses of water should be eliminated”).

In September, most of the regions were “normal” overall, according to the DEQ’s Drought Monitoring Task Force (DMTF), although the status of the four parameters varied within some regions. The Northern Piedmont, however, was the sole region declared to be under a drought “watch,” and it retained that status throughout the month. DEQ drought maps show our region in this period to have had “normal” precipitation and water in reservoirs, water flow at “warning” levels and groundwater — especially important in our county, where most of us are on wells — dropping to “emergency” levels.

In its Oct. 11 drought report, DMTF maintained the overall “watch” status for our region and extended the same status to three more regions running generally in a line through central Virginia, from the commonwealth’s northern to southern borders. Despite recent rain, by Oct. 14 precipitation levels sunk into “watch” status in our region, while groundwater remained at “emergency” levels and flow improved to “watch” status.

What all this means is that the prospects of good fall color are pretty bleak this year. When rain finally came last week, from the remnants of Hurricane Nate, it was likely too late to affect leaf color this fall and it brought down more leaves. I haven’t seen much color change at any elevation from Amissville to Skyline Drive up to when I filed this column (Oct. 16). Some of the leaves that have come down were from species that usually drop their leaves early without turning bright colors, such as tuliptrees and sycamores. But some of the usual stars of the show have also lost many of their leaves, or their leaves have hung on but turned brown.

Although fall color is unlikely to be at its best this year, this photo (taken on Oct. 16) shows that the view of Rappahannock County from Skyline Drive’s Little Devil’s Stairs overlook, is still always worth seeing. By Pam Owen

Some early fall stars, such as Virginia creeper and sassafras, were drooping, even after the rains came, and their colors were not as vibrant. Many sumacs, whose leaves usually start turning bright red even before fall begins, were the victims of the boom in pest insects the mild winter had produced, losing most or all of their leaves before they could turn color.

Sassafras is one of Virginia’s early producers of bright fall foliage, but will the long stretch of dry, hot conditions this year mute the usually spectacular show? By Pam Owen

According to the Virginia Department of Forestry, peak color in central Virginia, including the Northern Piedmont and the Blue Ridge Mountains, is Oct. 15–25, depending on the elevation. This means that, by the time this column is published on Oct. 19, we should start to see the real effect of the dry, warm weather on the fall color in our area.

In any case, the recent rain and cooler temperatures are still welcome. They will help the woody plants that have survived the dry spell stay alive, ready to join the show next year. And other organisms, including other plants, wildlife and fungi, are also benefiting. Most mushrooms love damp conditions, and before the rain this fall, I didn’t see any blooming in the usual places. But soon after the rain started, mushrooms shot up in my lawn and in the forest that surrounds it.

And the early rains this year, combined with an apparent boom in beneficial insects, such as pollinators, helped many woody plants produce bumper crops of food for wildlife — including soft mast, such as berries and grapes, and hard mast (nuts and acorns) — before the dry spell really kicked in.

Soft mast crops, such as these spicebush berries, did well this year, thanks to sufficient rain during the spring and summer and pollinators. By Pam Owen

© 2017 Pam Owen

Pam Owen
About Pam Owen 343 Articles
Writer, editor, photographer, and passionate nature conservationist living in Rappahannock County, in the Blue Ridge Mountains of Virginia. Two favorite quotes: By E.O. Wilson, who coined the term "biodiversity," "Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction”; by Douglas Adams, “I love deadlines. I love the whooshing sound they make as they pass by.”