Published: December 09, 2008 08:13 am      

Many trees holding onto leaves into December

Local News

“It’s the coldest time of winter.”

The lyrical line from “If We Make It Through December,” Merle Haggard’s 1973 classic, may not be meteorologically correct, but December normally has a bleak appearance of winter.

What’s happened this autumn? Why are so many trees still holding onto their leaves?

Despite frequent skifts of snow and temperatures below normal, hillside forests have a different look. Leaves, particularly on oak trees, have not fallen. Instead of bare twigs touching the skyline, woodlands are painted brown with stubborn foliage.

In residential areas, Bradford pears, a popular landscape tree, are also fully leafed. Some Bradford pears are still green, almost a summer-like look.

Oak trees don’t normally lose all leaves in winter, noted Beth Wilson, horticulturist at the Pulaski County Extension Office. She explained that a cone of juvenility (immaturity) forms early in the life of an oak tree resulting in leaves hanging on through the winter at the bottom or oldest part of the tree.

“It’s strange, but true,” said Wilson. However, she agrees with a couple of other experts that drought is always an issue in the current situation.

Connie Woodcock, service forester with the Kentucky Division of Forestry, pointed to two years of severe drought that have put stress on a lot of trees.

“They look as if they are dying,” said Woodcock. And this could be the case.

Mark Holman, chief forester with the Kentucky Division of Forestry, said drought two years in a row coupled with a hard freeze in April 2007 may have been more than a lot of trees can stand.

“Some trees may not recover,” Holman predicted.

“(Drought) has caused leaves to turn brown and hang on the trees instead of going through a normal fall,” Holman explained. He recalled that normal coloration was muted in many areas this autumn with leaves drying up and turning brown.

Washed-out fall colors in and around Pulaski County triggered a story in the Commonwealth Journal that we would miss autumn’s blazing show. However, shortly after the story was published, the few remaining leaves put on a stunningly beautiful response. The bright coloration was nearly three weeks later than normal, extending almost to mid-November.

“Hopefully, the trees are still alive,” Holman continued, alluding to the stressful weather conditions. He predicted that most of the brown leaves on oak trees will hang on until buds start coming out next spring.

“Snow, ice and rain may take some of them off,” he said, but most will hang on,” he added.

During a normal autumn, shorter days and less sunlight close veins that carry sap to leaves. A layer of cells, called a separation layer forms at the base of the leaf stem. It separates the leaf from the branch and the leaf floats groundward.

The only exception is oak. The separation layer never fully detaches the dead oak leaf, specifically at the oldest part near the bottom, and the lower leaves tend to hang on.

Apparently, because of severe drought, the separation layer that drops leaves to the ground didn’t form on some trees this autumn. And, as Holman suggests, leaves on a dead limb do not fall.

But, clinging leaves could be a progeny of hope, especially for those who have observed more than their share of autumns.

Sonny James, the Southern Gentleman, probably said it best in song: “I carry on till the last leaf shall fall ... ”